[{"ddc":["530"],"volume":1011,"publication_status":"published","tmp":{"image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","short":"CC BY (4.0)","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)"},"intvolume":"      1011","status":"public","title":"Rigid fibre transport in a periodic non-homogeneous geophysical turbulent flow","author":[{"last_name":"De Leo","full_name":"De Leo, Annalisa","first_name":"Annalisa"},{"last_name":"Brizzolara","full_name":"Brizzolara, Stefano","first_name":"Stefano","id":"4bbe33b8-c59a-11ee-a1af-fa33d1ac42c4"},{"last_name":"Cavaiola","full_name":"Cavaiola, Mattia","first_name":"Mattia"},{"first_name":"Junlin","full_name":"He, Junlin","last_name":"He"},{"full_name":"Stocchino, Alessandro","first_name":"Alessandro","last_name":"Stocchino"}],"ec_funded":1,"publisher":"Cambridge University Press","date_published":"2025-05-16T00:00:00Z","language":[{"iso":"eng"}],"user_id":"317138e5-6ab7-11ef-aa6d-ffef3953e345","has_accepted_license":"1","month":"05","scopus_import":"1","project":[{"_id":"fc2ed2f7-9c52-11eb-aca3-c01059dda49c","grant_number":"101034413","name":"IST-BRIDGE: International postdoctoral program","call_identifier":"H2020"}],"type":"journal_article","file":[{"creator":"dernst","date_created":"2025-05-28T08:12:07Z","relation":"main_file","success":1,"content_type":"application/pdf","checksum":"f1b0f6a977fdf2d6eb9e16c11d030c0c","file_id":"19751","access_level":"open_access","file_size":6415303,"date_updated":"2025-05-28T08:12:07Z","file_name":"2025_JourFluidMech_DeLeo.pdf"}],"doi":"10.1017/jfm.2025.362","external_id":{"isi":["001489159700001"]},"file_date_updated":"2025-05-28T08:12:07Z","publication":"Journal of Fluid Mechanics","date_created":"2025-05-25T22:16:46Z","article_type":"original","isi":1,"article_number":"A5","year":"2025","department":[{"_id":"BjHo"}],"date_updated":"2025-09-30T12:38:34Z","_id":"19729","abstract":[{"text":"From anthropogenic litter carried by ocean currents to plant stems travelling through the atmosphere, geophysical flows are often seeded with elongated, fibre-like particles. In this study, we used a large-scale laboratory model of a tidal current – representative of a widespread class of geophysical flows – to investigate the tumbling motion of long, slender and floating fibres in the complex turbulence generated by flow interactions with a tidal inlet. Despite the non-stationary, non-homogeneous and anisotropic nature of this turbulence, we find that long fibres statistically rotate at the same frequency as eddies of similar size, a phenomenon called scale selection, which is known to occur in ideal turbulence. Furthermore, we report that the signal of the instantaneous transverse velocity difference between the fibre ends changes significantly from the signal produced by the flow in the fibre surroundings, although the two are statistically equivalent. These observations have twofold implications. On the one hand, they confirm the reliability of using the end-to-end velocity signal of rigid fibres to probe the two-point transverse statistics of the flow, even under realistic conditions: oceanographers could exploit this observation to measure transverse velocity differences through elongated floats in the field, where superdiffusion complicates collecting sufficient data to probe two-point turbulence statistics at a fixed separation effectively. On the other hand, by addressing the dynamics of inertial range particles floating in the coastal zone, these observations are crucial to improving our ability to predict the fate of meso- and macro-litter, a size class that is currently understudied.","lang":"eng"}],"acknowledgement":"A.S. expresses thanks for support from the Research Grants Council of Hong Kong (project IDs 15216422 and C5032-22EF) and from the Research Institute for Land and Space (RILS) (project ID P0049622). S.B. is funded by the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement (no.101034413).","quality_controlled":"1","publication_identifier":{"issn":["0022-1120"],"eissn":["1469-7645"]},"OA_type":"hybrid","citation":{"apa":"De Leo, A., Brizzolara, S., Cavaiola, M., He, J., &#38; Stocchino, A. (2025). Rigid fibre transport in a periodic non-homogeneous geophysical turbulent flow. <i>Journal of Fluid Mechanics</i>. Cambridge University Press. <a href=\"https://doi.org/10.1017/jfm.2025.362\">https://doi.org/10.1017/jfm.2025.362</a>","short":"A. De Leo, S. Brizzolara, M. Cavaiola, J. He, A. Stocchino, Journal of Fluid Mechanics 1011 (2025).","chicago":"De Leo, Annalisa, Stefano Brizzolara, Mattia Cavaiola, Junlin He, and Alessandro Stocchino. “Rigid Fibre Transport in a Periodic Non-Homogeneous Geophysical Turbulent Flow.” <i>Journal of Fluid Mechanics</i>. Cambridge University Press, 2025. <a href=\"https://doi.org/10.1017/jfm.2025.362\">https://doi.org/10.1017/jfm.2025.362</a>.","ieee":"A. De Leo, S. Brizzolara, M. Cavaiola, J. He, and A. Stocchino, “Rigid fibre transport in a periodic non-homogeneous geophysical turbulent flow,” <i>Journal of Fluid Mechanics</i>, vol. 1011. Cambridge University Press, 2025.","mla":"De Leo, Annalisa, et al. “Rigid Fibre Transport in a Periodic Non-Homogeneous Geophysical Turbulent Flow.” <i>Journal of Fluid Mechanics</i>, vol. 1011, A5, Cambridge University Press, 2025, doi:<a href=\"https://doi.org/10.1017/jfm.2025.362\">10.1017/jfm.2025.362</a>.","ista":"De Leo A, Brizzolara S, Cavaiola M, He J, Stocchino A. 2025. Rigid fibre transport in a periodic non-homogeneous geophysical turbulent flow. Journal of Fluid Mechanics. 1011, A5.","ama":"De Leo A, Brizzolara S, Cavaiola M, He J, Stocchino A. Rigid fibre transport in a periodic non-homogeneous geophysical turbulent flow. <i>Journal of Fluid Mechanics</i>. 2025;1011. doi:<a href=\"https://doi.org/10.1017/jfm.2025.362\">10.1017/jfm.2025.362</a>"},"article_processing_charge":"No","day":"16","oa_version":"Published Version","OA_place":"publisher","oa":1},{"file_date_updated":"2025-05-28T08:32:33Z","external_id":{"isi":["001487354900001"]},"doi":"10.1017/jfm.2025.278","publication":"Journal of Fluid Mechanics","file":[{"creator":"dernst","date_created":"2025-05-28T08:32:33Z","checksum":"77f39b762a0e59e88954afb93b23cc7a","relation":"main_file","success":1,"content_type":"application/pdf","date_updated":"2025-05-28T08:32:33Z","file_size":3607069,"file_name":"2025_JourFluidMech_Wang.pdf","file_id":"19752","access_level":"open_access"}],"type":"journal_article","user_id":"317138e5-6ab7-11ef-aa6d-ffef3953e345","scopus_import":"1","project":[{"call_identifier":"H2020","name":"IST-BRIDGE: International postdoctoral program","_id":"fc2ed2f7-9c52-11eb-aca3-c01059dda49c","grant_number":"101034413"},{"grant_number":"ESP 1481224","_id":"942a0200-16d5-11f0-9cad-f48ab22dfd1c","name":"Pattern Formation Mechanisms in Planar Shear Flows"}],"month":"05","has_accepted_license":"1","language":[{"iso":"eng"}],"title":"Feigenbaum universality in subcritical Taylor-Couette flow","date_published":"2025-05-14T00:00:00Z","publisher":"Cambridge University Press","author":[{"first_name":"Baoying","full_name":"Wang, Baoying","last_name":"Wang","id":"df755ffe-735a-11ee-bb55-dff29d61d338","orcid":"0000-0002-6229-0336"},{"first_name":"Roger","full_name":"Ayats López, Roger","last_name":"Ayats López","orcid":"0000-0001-6572-0621","id":"ab77522d-073b-11ed-8aff-e71b39258362"},{"first_name":"K.","full_name":"Deguchi, K.","last_name":"Deguchi"},{"last_name":"Meseguer","first_name":"A.","full_name":"Meseguer, A."},{"last_name":"Mellibovsky","full_name":"Mellibovsky, F.","first_name":"F."}],"ec_funded":1,"status":"public","intvolume":"      1010","ddc":["530"],"volume":1010,"publication_status":"published","tmp":{"image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","short":"CC BY (4.0)","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)"},"oa":1,"OA_place":"publisher","day":"14","oa_version":"Published Version","citation":{"apa":"Wang, B., Ayats López, R., Deguchi, K., Meseguer, A., &#38; Mellibovsky, F. (2025). Feigenbaum universality in subcritical Taylor-Couette flow. <i>Journal of Fluid Mechanics</i>. Cambridge University Press. <a href=\"https://doi.org/10.1017/jfm.2025.278\">https://doi.org/10.1017/jfm.2025.278</a>","short":"B. Wang, R. Ayats López, K. Deguchi, A. Meseguer, F. Mellibovsky, Journal of Fluid Mechanics 1010 (2025).","ieee":"B. Wang, R. Ayats López, K. Deguchi, A. Meseguer, and F. Mellibovsky, “Feigenbaum universality in subcritical Taylor-Couette flow,” <i>Journal of Fluid Mechanics</i>, vol. 1010. Cambridge University Press, 2025.","chicago":"Wang, Baoying, Roger Ayats López, K. Deguchi, A. Meseguer, and F. Mellibovsky. “Feigenbaum Universality in Subcritical Taylor-Couette Flow.” <i>Journal of Fluid Mechanics</i>. Cambridge University Press, 2025. <a href=\"https://doi.org/10.1017/jfm.2025.278\">https://doi.org/10.1017/jfm.2025.278</a>.","mla":"Wang, Baoying, et al. “Feigenbaum Universality in Subcritical Taylor-Couette Flow.” <i>Journal of Fluid Mechanics</i>, vol. 1010, A36, Cambridge University Press, 2025, doi:<a href=\"https://doi.org/10.1017/jfm.2025.278\">10.1017/jfm.2025.278</a>.","ama":"Wang B, Ayats López R, Deguchi K, Meseguer A, Mellibovsky F. Feigenbaum universality in subcritical Taylor-Couette flow. <i>Journal of Fluid Mechanics</i>. 2025;1010. doi:<a href=\"https://doi.org/10.1017/jfm.2025.278\">10.1017/jfm.2025.278</a>","ista":"Wang B, Ayats López R, Deguchi K, Meseguer A, Mellibovsky F. 2025. Feigenbaum universality in subcritical Taylor-Couette flow. Journal of Fluid Mechanics. 1010, A36."},"article_processing_charge":"Yes (in subscription journal)","publication_identifier":{"issn":["0022-1120"],"eissn":["1469-7645"]},"OA_type":"hybrid","_id":"19730","quality_controlled":"1","acknowledgement":"This research is supported by the Australian Research Council Discovery Project DP230102188 and the Ministerio de Ciencia, Innovación y Universidades (Agencia Estatal de Investigación, project nos. PID 2020–114043 GB-I00 (MCIN/AEI/10.13039/501100011033) and PID 2023–150029NB-I00 (MCIN/AEI/10.13039/501100011033/FEDER, UE). B.W.’s and R.A.’s research has been funded by the European Union’s Horizon 2020 research and innovation programme (Marie Skłodowska-Curie Grant Agreement No. 101034413). R.A. has also been funded by the Austrian Science Fund (FWF) 10.55776/ESP1481224.","abstract":[{"text":"Feigenbaum universality is shown to occur in subcritical shear flows. Our testing ground is the counter-rotation regime of the Taylor–Couette flow, where numerical calculations are performed within a small periodic domain. The accurate computation of up to the seventh period-doubling bifurcation, assisted by a purposely defined Poincaré section, has enabled us to reproduce the two Feigenbaum universal constants with unprecedented accuracy in a fluid flow problem. We have further devised a method to predict the bifurcation diagram up to the accumulation point of the cascade based on the detailed inspection of just the first few period-doubling bifurcations. Remarkably, the method is applicable beyond the accumulation point, with predictions remaining valid, in a statistical sense, for the chaotic dynamics that follows.","lang":"eng"}],"date_updated":"2025-09-30T12:39:05Z","department":[{"_id":"BjHo"}],"year":"2025","isi":1,"article_type":"original","article_number":"A36","date_created":"2025-05-25T22:16:48Z"},{"date_created":"2025-05-25T22:16:52Z","article_number":"R2","article_type":"original","isi":1,"year":"2025","date_updated":"2025-09-30T12:39:44Z","department":[{"_id":"BjHo"}],"abstract":[{"lang":"eng","text":"The transition to chaos in the subcritical regime of counter-rotating Taylor–Couette flow is investigated using a minimal periodic domain capable of sustaining coherent structures. Following a Feigenbaum cascade, the dynamics is found to be remarkably well approximated by a simple discrete map that admits rigorous proof of its chaotic nature. The chaotic set that arises for the map features densely distributed periodic points that are in one-to-one correspondence with unstable periodic orbits (UPOs) of the Navier–Stokes system. This supports the increasingly accepted view that UPOs may serve as the backbone of turbulence and, indeed, we demonstrate that it is possible to reconstruct every statistical property of chaotic fluid flow from UPOs."}],"acknowledgement":"This research is supported by the Australian Research Council Discovery Project DP230102188 and the Ministerio de Ciencia, Innovación y Universidades (Agencia Estatal de Investigación, project nos PID 2020-114043 GB-I00 (MCIN/AEI/10.13039/501100011033) and PID 2023-150029NB-I00 (MCIN/AEI/10.13039/ 501100011033/FEDER, UE). B.W. and R.A.’s research has been funded by the European Union’s Horizon 2020 research and innovation programme (Marie Skłodowska-Curie grant agreement no. 101034413). R.A. has also been funded by the Austrian Science Fund (FWF) 10.55776/ESP1481224.","quality_controlled":"1","_id":"19732","OA_type":"hybrid","publication_identifier":{"eissn":["1469-7645"],"issn":["0022-1120"]},"article_processing_charge":"Yes (in subscription journal)","citation":{"mla":"Wang, Baoying, et al. “Mathematically Established Chaos and Forecast of Statistics with Recurrent Patterns in Taylor-Couette Flow.” <i>Journal of Fluid Mechanics</i>, vol. 1011, R2, Cambridge University Press, 2025, doi:<a href=\"https://doi.org/10.1017/jfm.2025.151\">10.1017/jfm.2025.151</a>.","ama":"Wang B, Ayats López R, Deguchi K, Meseguer A, Mellibovsky F. Mathematically established chaos and forecast of statistics with recurrent patterns in Taylor-Couette flow. <i>Journal of Fluid Mechanics</i>. 2025;1011. doi:<a href=\"https://doi.org/10.1017/jfm.2025.151\">10.1017/jfm.2025.151</a>","ista":"Wang B, Ayats López R, Deguchi K, Meseguer A, Mellibovsky F. 2025. Mathematically established chaos and forecast of statistics with recurrent patterns in Taylor-Couette flow. Journal of Fluid Mechanics. 1011, R2.","short":"B. Wang, R. Ayats López, K. Deguchi, A. Meseguer, F. Mellibovsky, Journal of Fluid Mechanics 1011 (2025).","apa":"Wang, B., Ayats López, R., Deguchi, K., Meseguer, A., &#38; Mellibovsky, F. (2025). Mathematically established chaos and forecast of statistics with recurrent patterns in Taylor-Couette flow. <i>Journal of Fluid Mechanics</i>. Cambridge University Press. <a href=\"https://doi.org/10.1017/jfm.2025.151\">https://doi.org/10.1017/jfm.2025.151</a>","ieee":"B. Wang, R. Ayats López, K. Deguchi, A. Meseguer, and F. Mellibovsky, “Mathematically established chaos and forecast of statistics with recurrent patterns in Taylor-Couette flow,” <i>Journal of Fluid Mechanics</i>, vol. 1011. Cambridge University Press, 2025.","chicago":"Wang, Baoying, Roger Ayats López, K. Deguchi, A. Meseguer, and F. Mellibovsky. “Mathematically Established Chaos and Forecast of Statistics with Recurrent Patterns in Taylor-Couette Flow.” <i>Journal of Fluid Mechanics</i>. Cambridge University Press, 2025. <a href=\"https://doi.org/10.1017/jfm.2025.151\">https://doi.org/10.1017/jfm.2025.151</a>."},"day":"13","oa_version":"Published Version","OA_place":"publisher","oa":1,"publication_status":"published","tmp":{"image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","short":"CC BY (4.0)","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)"},"ddc":["530"],"volume":1011,"intvolume":"      1011","status":"public","author":[{"first_name":"Baoying","full_name":"Wang, Baoying","last_name":"Wang","id":"df755ffe-735a-11ee-bb55-dff29d61d338","orcid":"0000-0002-6229-0336"},{"last_name":"Ayats López","first_name":"Roger","full_name":"Ayats López, Roger","orcid":"0000-0001-6572-0621","id":"ab77522d-073b-11ed-8aff-e71b39258362"},{"first_name":"K.","full_name":"Deguchi, K.","last_name":"Deguchi"},{"first_name":"A.","full_name":"Meseguer, A.","last_name":"Meseguer"},{"last_name":"Mellibovsky","full_name":"Mellibovsky, F.","first_name":"F."}],"ec_funded":1,"publisher":"Cambridge University Press","date_published":"2025-05-13T00:00:00Z","title":"Mathematically established chaos and forecast of statistics with recurrent patterns in Taylor-Couette flow","language":[{"iso":"eng"}],"has_accepted_license":"1","month":"05","scopus_import":"1","project":[{"grant_number":"101034413","_id":"fc2ed2f7-9c52-11eb-aca3-c01059dda49c","name":"IST-BRIDGE: International postdoctoral program","call_identifier":"H2020"},{"name":"Pattern Formation Mechanisms in Planar Shear Flows","_id":"942a0200-16d5-11f0-9cad-f48ab22dfd1c","grant_number":"ESP 1481224"}],"user_id":"317138e5-6ab7-11ef-aa6d-ffef3953e345","type":"journal_article","file":[{"checksum":"899df5797844a9e811dffeebe8c05c8e","content_type":"application/pdf","success":1,"relation":"main_file","file_name":"2025_JourFluidMech_Wang_Ayats.pdf","file_size":998754,"date_updated":"2025-05-28T09:00:52Z","access_level":"open_access","file_id":"19754","creator":"dernst","date_created":"2025-05-28T09:00:52Z"}],"publication":"Journal of Fluid Mechanics","external_id":{"isi":["001486096600001"]},"doi":"10.1017/jfm.2025.151","file_date_updated":"2025-05-28T09:00:52Z"},{"corr_author":"1","user_id":"4359f0d1-fa6c-11eb-b949-802e58b17ae8","month":"01","has_accepted_license":"1","project":[{"_id":"238598C6-32DE-11EA-91FC-C7463DDC885E","grant_number":"662960","name":"Revisiting the Turbulence Problem Using Statistical Mechanics"}],"scopus_import":"1","type":"journal_article","file":[{"file_name":"2023_JourFluidMechanics_Marensi.pdf","file_size":1931647,"date_updated":"2023-02-02T12:34:54Z","access_level":"open_access","file_id":"12489","checksum":"9224f987caefe5dd85a70814d3cce65c","content_type":"application/pdf","relation":"main_file","success":1,"date_created":"2023-02-02T12:34:54Z","creator":"dernst"}],"doi":"10.1017/jfm.2022.1001","external_id":{"arxiv":["2101.07516"],"isi":["000903336600001"]},"file_date_updated":"2023-02-02T12:34:54Z","publication":"Journal of Fluid Mechanics","ddc":["530"],"volume":954,"tmp":{"image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","short":"CC BY (4.0)","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)"},"publication_status":"published","intvolume":"       954","status":"public","title":"Symmetry-reduced dynamic mode decomposition of near-wall turbulence","author":[{"orcid":"0000-0001-7173-4923","id":"0BE7553A-1004-11EA-B805-18983DDC885E","full_name":"Marensi, Elena","first_name":"Elena","last_name":"Marensi"},{"full_name":"Yalniz, Gökhan","first_name":"Gökhan","last_name":"Yalniz","id":"66E74FA2-D8BF-11E9-8249-8DE2E5697425","orcid":"0000-0002-8490-9312"},{"orcid":"0000-0003-2057-2754","id":"3A374330-F248-11E8-B48F-1D18A9856A87","full_name":"Hof, Björn","first_name":"Björn","last_name":"Hof"},{"full_name":"Budanur, Nazmi B","first_name":"Nazmi B","last_name":"Budanur","orcid":"0000-0003-0423-5010","id":"3EA1010E-F248-11E8-B48F-1D18A9856A87"}],"publisher":"Cambridge University Press","date_published":"2023-01-10T00:00:00Z","language":[{"iso":"eng"}],"publication_identifier":{"eissn":["1469-7645"],"issn":["0022-1120"]},"citation":{"mla":"Marensi, Elena, et al. “Symmetry-Reduced Dynamic Mode Decomposition of near-Wall Turbulence.” <i>Journal of Fluid Mechanics</i>, vol. 954, A10, Cambridge University Press, 2023, doi:<a href=\"https://doi.org/10.1017/jfm.2022.1001\">10.1017/jfm.2022.1001</a>.","ama":"Marensi E, Yalniz G, Hof B, Budanur NB. Symmetry-reduced dynamic mode decomposition of near-wall turbulence. <i>Journal of Fluid Mechanics</i>. 2023;954. doi:<a href=\"https://doi.org/10.1017/jfm.2022.1001\">10.1017/jfm.2022.1001</a>","ista":"Marensi E, Yalniz G, Hof B, Budanur NB. 2023. Symmetry-reduced dynamic mode decomposition of near-wall turbulence. Journal of Fluid Mechanics. 954, A10.","apa":"Marensi, E., Yalniz, G., Hof, B., &#38; Budanur, N. B. (2023). Symmetry-reduced dynamic mode decomposition of near-wall turbulence. <i>Journal of Fluid Mechanics</i>. Cambridge University Press. <a href=\"https://doi.org/10.1017/jfm.2022.1001\">https://doi.org/10.1017/jfm.2022.1001</a>","short":"E. Marensi, G. Yalniz, B. Hof, N.B. Budanur, Journal of Fluid Mechanics 954 (2023).","chicago":"Marensi, Elena, Gökhan Yalniz, Björn Hof, and Nazmi B Budanur. “Symmetry-Reduced Dynamic Mode Decomposition of near-Wall Turbulence.” <i>Journal of Fluid Mechanics</i>. Cambridge University Press, 2023. <a href=\"https://doi.org/10.1017/jfm.2022.1001\">https://doi.org/10.1017/jfm.2022.1001</a>.","ieee":"E. Marensi, G. Yalniz, B. Hof, and N. B. Budanur, “Symmetry-reduced dynamic mode decomposition of near-wall turbulence,” <i>Journal of Fluid Mechanics</i>, vol. 954. Cambridge University Press, 2023."},"article_processing_charge":"Yes (via OA deal)","day":"10","oa_version":"Published Version","oa":1,"date_created":"2023-01-08T23:00:53Z","arxiv":1,"article_type":"original","isi":1,"article_number":"A10","year":"2023","related_material":{"record":[{"relation":"dissertation_contains","status":"public","id":"19684"}]},"department":[{"_id":"BjHo"}],"date_updated":"2026-04-07T11:47:05Z","_id":"12105","abstract":[{"lang":"eng","text":"Data-driven dimensionality reduction methods such as proper orthogonal decomposition and dynamic mode decomposition have proven to be useful for exploring complex phenomena within fluid dynamics and beyond. A well-known challenge for these techniques is posed by the continuous symmetries, e.g. translations and rotations, of the system under consideration, as drifts in the data dominate the modal expansions without providing an insight into the dynamics of the problem. In the present study, we address this issue for fluid flows in rectangular channels by formulating a continuous symmetry reduction method that eliminates the translations in the streamwise and spanwise directions simultaneously. We demonstrate our method by computing the symmetry-reduced dynamic mode decomposition (SRDMD) of sliding windows of data obtained from the transitional plane-Couette and turbulent plane-Poiseuille flow simulations. In the former setting, SRDMD captures the dynamics in the vicinity of the invariant solutions with translation symmetries, i.e. travelling waves and relative periodic orbits, whereas in the latter, our calculations reveal episodes of turbulent time evolution that can be approximated by a low-dimensional linear expansion."}],"acknowledgement":"E.M. acknowledges funding from the ISTplus fellowship programme. G.Y. and B.H. acknowledge\r\na grant from the Simons Foundation (662960, BH).","quality_controlled":"1"},{"citation":{"chicago":"Marensi, Elena, Gökhan Yalniz, and Björn Hof. “Dynamics and Proliferation of Turbulent Stripes in Plane-Poiseuille and Plane-Couette Flows.” <i>Journal of Fluid Mechanics</i>. Cambridge University Press, 2023. <a href=\"https://doi.org/10.1017/jfm.2023.780\">https://doi.org/10.1017/jfm.2023.780</a>.","ieee":"E. Marensi, G. Yalniz, and B. Hof, “Dynamics and proliferation of turbulent stripes in plane-Poiseuille and plane-Couette flows,” <i>Journal of Fluid Mechanics</i>, vol. 974. Cambridge University Press, 2023.","apa":"Marensi, E., Yalniz, G., &#38; Hof, B. (2023). Dynamics and proliferation of turbulent stripes in plane-Poiseuille and plane-Couette flows. <i>Journal of Fluid Mechanics</i>. Cambridge University Press. <a href=\"https://doi.org/10.1017/jfm.2023.780\">https://doi.org/10.1017/jfm.2023.780</a>","short":"E. Marensi, G. Yalniz, B. Hof, Journal of Fluid Mechanics 974 (2023).","ama":"Marensi E, Yalniz G, Hof B. Dynamics and proliferation of turbulent stripes in plane-Poiseuille and plane-Couette flows. <i>Journal of Fluid Mechanics</i>. 2023;974. doi:<a href=\"https://doi.org/10.1017/jfm.2023.780\">10.1017/jfm.2023.780</a>","ista":"Marensi E, Yalniz G, Hof B. 2023. Dynamics and proliferation of turbulent stripes in plane-Poiseuille and plane-Couette flows. Journal of Fluid Mechanics. 974, A21.","mla":"Marensi, Elena, et al. “Dynamics and Proliferation of Turbulent Stripes in Plane-Poiseuille and Plane-Couette Flows.” <i>Journal of Fluid Mechanics</i>, vol. 974, A21, Cambridge University Press, 2023, doi:<a href=\"https://doi.org/10.1017/jfm.2023.780\">10.1017/jfm.2023.780</a>."},"article_processing_charge":"Yes (via OA deal)","publication_identifier":{"eissn":["1469-7645"],"issn":["0022-1120"]},"oa":1,"keyword":["turbulence","transition to turbulence","patterns"],"day":"10","oa_version":"Published Version","isi":1,"article_type":"original","article_number":"A21","date_created":"2023-10-30T09:32:28Z","arxiv":1,"_id":"14466","quality_controlled":"1","acknowledgement":"E.M. acknowledges funding from the ISTplus fellowship programme. G.Y. and B.H. acknowledge a grant from the Simons Foundation (662960, BH).","abstract":[{"text":"The first long-lived turbulent structures observable in planar shear flows take the form of localized stripes, inclined with respect to the mean flow direction. The dynamics of these stripes is central to transition, and recent studies proposed an analogy to directed percolation where the stripes’ proliferation is ultimately responsible for the turbulence becoming sustained. In the present study we focus on the internal stripe dynamics as well as on the eventual stripe expansion, and we compare the underlying mechanisms in pressure- and shear-driven planar flows, respectively, plane-Poiseuille and plane-Couette flow. Despite the similarities of the overall laminar–turbulence patterns, the stripe proliferation processes in the two cases are fundamentally different. Starting from the growth and sustenance of individual stripes, we find that in plane-Couette flow new streaks are created stochastically throughout the stripe whereas in plane-Poiseuille flow streak creation is deterministic and occurs locally at the downstream tip. Because of the up/downstream symmetry, Couette stripes, in contrast to Poiseuille stripes, have two weak and two strong laminar turbulent interfaces. These differences in symmetry as well as in internal growth give rise to two fundamentally different stripe splitting mechanisms. In plane-Poiseuille flow splitting is connected to the elongational growth of the original stripe, and it results from a break-off/shedding of the stripe's tail. In plane-Couette flow splitting follows from a broadening of the original stripe and a division along the stripe into two slimmer stripes.","lang":"eng"}],"department":[{"_id":"GradSch"},{"_id":"BjHo"}],"date_updated":"2026-04-07T11:47:05Z","related_material":{"record":[{"relation":"dissertation_contains","status":"public","id":"19684"}]},"year":"2023","type":"journal_article","corr_author":"1","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","scopus_import":"1","project":[{"name":"Revisiting the Turbulence Problem Using Statistical Mechanics","grant_number":"662960","_id":"238598C6-32DE-11EA-91FC-C7463DDC885E"}],"has_accepted_license":"1","month":"11","file_date_updated":"2024-02-15T09:05:21Z","external_id":{"isi":["001088363700001"],"arxiv":["2212.12406"]},"doi":"10.1017/jfm.2023.780","publication":"Journal of Fluid Mechanics","file":[{"date_created":"2024-02-15T09:05:21Z","creator":"dernst","file_name":"2023_JourFluidMechanics_Marensi.pdf","file_size":2804641,"date_updated":"2024-02-15T09:05:21Z","access_level":"open_access","file_id":"14996","checksum":"17c64c1fb0d5f73252364bf98b0b9e1a","content_type":"application/pdf","success":1,"relation":"main_file"}],"status":"public","intvolume":"       974","ddc":["530"],"volume":974,"tmp":{"image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","short":"CC BY (4.0)","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)"},"publication_status":"published","language":[{"iso":"eng"}],"title":"Dynamics and proliferation of turbulent stripes in plane-Poiseuille and plane-Couette flows","date_published":"2023-11-10T00:00:00Z","publisher":"Cambridge University Press","author":[{"last_name":"Marensi","first_name":"Elena","full_name":"Marensi, Elena","orcid":"0000-0001-7173-4923","id":"0BE7553A-1004-11EA-B805-18983DDC885E"},{"id":"66E74FA2-D8BF-11E9-8249-8DE2E5697425","orcid":"0000-0002-8490-9312","last_name":"Yalniz","full_name":"Yalniz, Gökhan","first_name":"Gökhan"},{"orcid":"0000-0003-2057-2754","id":"3A374330-F248-11E8-B48F-1D18A9856A87","full_name":"Hof, Björn","first_name":"Björn","last_name":"Hof"}]},{"language":[{"iso":"eng"}],"title":"On the wavenumber-frequency spectrum of the wall pressure fluctuations in turbulent channel flow","author":[{"id":"71b6ff4b-15b2-11ec-abd3-aef6b028cf7e","orcid":"0000-0002-4843-6853","last_name":"Yang","full_name":"Yang, Bowen","first_name":"Bowen"},{"last_name":"Yang","first_name":"Zixuan","full_name":"Yang, Zixuan"}],"date_published":"2022-04-25T00:00:00Z","publisher":"Cambridge University Press","intvolume":"       937","status":"public","ddc":["530"],"volume":937,"publication_status":"published","external_id":{"isi":["000763547000001"],"arxiv":["2201.04702"]},"doi":"10.1017/jfm.2022.137","publication":"Journal of Fluid Mechanics","type":"journal_article","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","month":"04","scopus_import":"1","_id":"10925","acknowledgement":"This research is supported by the NSFC Basic Science Center Program for ‘Multiscale Problems in Nonlinear Mechanics’ (no. 11988102), National Key Project (GJXM92579) and the Strategic Priority Research Program (XDB22040104).","abstract":[{"lang":"eng","text":"Direct numerical simulations (DNS) of turbulent channel flows up to  Reτ≈1000  are conducted to investigate the three-dimensional (consisting of streamwise wavenumber, spanwise wavenumber and frequency) spectrum of wall pressure fluctuations. To develop a predictive model of the wavenumber–frequency spectrum from the wavenumber spectrum, the time decorrelation mechanisms of wall pressure fluctuations are investigated. It is discovered that the energy-containing part of the wavenumber–frequency spectrum of wall pressure fluctuations can be well predicted using a similar random sweeping model for streamwise velocity fluctuations. To refine the investigation, we further decompose the spectrum of the total wall pressure fluctuations into the autospectra of rapid and slow pressure fluctuations, and the cross-spectrum between them. We focus on evaluating the assumption applied in many predictive models, that is, the magnitude of the cross-spectrum is negligibly small. The present DNS shows that neglecting the cross-spectrum causes a maximum error up to 4.7 dB in the subconvective region for all Reynolds numbers under test. Our analyses indicate that the approximation of neglecting the cross-spectrum needs to be applied carefully in the investigations of acoustics at low Mach numbers, in which the subconvective components of wall pressure fluctuations make important contributions to the radiated acoustic power."}],"quality_controlled":"1","year":"2022","date_updated":"2026-06-18T10:46:00Z","department":[{"_id":"GradSch"}],"article_type":"original","isi":1,"main_file_link":[{"open_access":"1","url":"https://doi.org/10.1017/jfm.2022.137"}],"article_number":"A39","date_created":"2022-03-27T22:01:45Z","arxiv":1,"oa":1,"day":"25","oa_version":"Published Version","citation":{"ieee":"B. Yang and Z. Yang, “On the wavenumber-frequency spectrum of the wall pressure fluctuations in turbulent channel flow,” <i>Journal of Fluid Mechanics</i>, vol. 937. Cambridge University Press, 2022.","chicago":"Yang, Bowen, and Zixuan Yang. “On the Wavenumber-Frequency Spectrum of the Wall Pressure Fluctuations in Turbulent Channel Flow.” <i>Journal of Fluid Mechanics</i>. Cambridge University Press, 2022. <a href=\"https://doi.org/10.1017/jfm.2022.137\">https://doi.org/10.1017/jfm.2022.137</a>.","short":"B. Yang, Z. Yang, Journal of Fluid Mechanics 937 (2022).","apa":"Yang, B., &#38; Yang, Z. (2022). On the wavenumber-frequency spectrum of the wall pressure fluctuations in turbulent channel flow. <i>Journal of Fluid Mechanics</i>. Cambridge University Press. <a href=\"https://doi.org/10.1017/jfm.2022.137\">https://doi.org/10.1017/jfm.2022.137</a>","ama":"Yang B, Yang Z. On the wavenumber-frequency spectrum of the wall pressure fluctuations in turbulent channel flow. <i>Journal of Fluid Mechanics</i>. 2022;937. doi:<a href=\"https://doi.org/10.1017/jfm.2022.137\">10.1017/jfm.2022.137</a>","ista":"Yang B, Yang Z. 2022. On the wavenumber-frequency spectrum of the wall pressure fluctuations in turbulent channel flow. Journal of Fluid Mechanics. 937, A39.","mla":"Yang, Bowen, and Zixuan Yang. “On the Wavenumber-Frequency Spectrum of the Wall Pressure Fluctuations in Turbulent Channel Flow.” <i>Journal of Fluid Mechanics</i>, vol. 937, A39, Cambridge University Press, 2022, doi:<a href=\"https://doi.org/10.1017/jfm.2022.137\">10.1017/jfm.2022.137</a>."},"article_processing_charge":"No","publication_identifier":{"eissn":["1469-7645"],"issn":["0022-1120"]}},{"scopus_import":"1","month":"11","user_id":"4359f0d1-fa6c-11eb-b949-802e58b17ae8","type":"journal_article","publication":"Journal of Fluid Mechanics","external_id":{"isi":["000879446900001"],"arxiv":["2207.12990"]},"doi":"10.1017/jfm.2022.828","publication_status":"published","volume":951,"status":"public","intvolume":"       951","publisher":"Cambridge University Press","date_published":"2022-11-07T00:00:00Z","author":[{"last_name":"Wang","first_name":"B.","full_name":"Wang, B."},{"full_name":"Ayats López, Roger","first_name":"Roger","last_name":"Ayats López","id":"ab77522d-073b-11ed-8aff-e71b39258362","orcid":"0000-0001-6572-0621"},{"last_name":"Deguchi","first_name":"K.","full_name":"Deguchi, K."},{"first_name":"F.","full_name":"Mellibovsky, F.","last_name":"Mellibovsky"},{"full_name":"Meseguer, A.","first_name":"A.","last_name":"Meseguer"}],"title":"Self-sustainment of coherent structures in counter-rotating Taylor–Couette flow","language":[{"iso":"eng"}],"publication_identifier":{"eissn":["1469-7645"],"issn":["0022-1120"]},"article_processing_charge":"No","citation":{"ama":"Wang B, Ayats López R, Deguchi K, Mellibovsky F, Meseguer A. Self-sustainment of coherent structures in counter-rotating Taylor–Couette flow. <i>Journal of Fluid Mechanics</i>. 2022;951. doi:<a href=\"https://doi.org/10.1017/jfm.2022.828\">10.1017/jfm.2022.828</a>","ista":"Wang B, Ayats López R, Deguchi K, Mellibovsky F, Meseguer A. 2022. Self-sustainment of coherent structures in counter-rotating Taylor–Couette flow. Journal of Fluid Mechanics. 951, A21.","mla":"Wang, B., et al. “Self-Sustainment of Coherent Structures in Counter-Rotating Taylor–Couette Flow.” <i>Journal of Fluid Mechanics</i>, vol. 951, A21, Cambridge University Press, 2022, doi:<a href=\"https://doi.org/10.1017/jfm.2022.828\">10.1017/jfm.2022.828</a>.","chicago":"Wang, B., Roger Ayats López, K. Deguchi, F. Mellibovsky, and A. Meseguer. “Self-Sustainment of Coherent Structures in Counter-Rotating Taylor–Couette Flow.” <i>Journal of Fluid Mechanics</i>. Cambridge University Press, 2022. <a href=\"https://doi.org/10.1017/jfm.2022.828\">https://doi.org/10.1017/jfm.2022.828</a>.","ieee":"B. Wang, R. Ayats López, K. Deguchi, F. Mellibovsky, and A. Meseguer, “Self-sustainment of coherent structures in counter-rotating Taylor–Couette flow,” <i>Journal of Fluid Mechanics</i>, vol. 951. Cambridge University Press, 2022.","apa":"Wang, B., Ayats López, R., Deguchi, K., Mellibovsky, F., &#38; Meseguer, A. (2022). Self-sustainment of coherent structures in counter-rotating Taylor–Couette flow. <i>Journal of Fluid Mechanics</i>. Cambridge University Press. <a href=\"https://doi.org/10.1017/jfm.2022.828\">https://doi.org/10.1017/jfm.2022.828</a>","short":"B. Wang, R. Ayats López, K. Deguchi, F. Mellibovsky, A. Meseguer, Journal of Fluid Mechanics 951 (2022)."},"day":"07","oa_version":"Preprint","oa":1,"keyword":["Mechanical Engineering","Mechanics of Materials","Condensed Matter Physics","Applied Mathematics"],"arxiv":1,"date_created":"2023-01-12T12:04:17Z","main_file_link":[{"url":" https://doi.org/10.48550/arXiv.2207.12990","open_access":"1"}],"article_number":"A21","isi":1,"article_type":"original","date_updated":"2023-08-04T08:54:16Z","department":[{"_id":"BjHo"}],"year":"2022","quality_controlled":"1","abstract":[{"lang":"eng","text":"We investigate the local self-sustained process underlying spiral turbulence in counter-rotating Taylor–Couette flow using a periodic annular domain, shaped as a parallelogram, two of whose sides are aligned with the cylindrical helix described by the spiral pattern. The primary focus of the study is placed on the emergence of drifting–rotating waves (DRW) that capture, in a relatively small domain, the main features of coherent structures typically observed in developed turbulence. The transitional dynamics of the subcritical region, far below the first instability of the laminar circular Couette flow, is determined by the upper and lower branches of DRW solutions originated at saddle-node bifurcations. The mechanism whereby these solutions self-sustain, and the chaotic dynamics they induce, are conspicuously reminiscent of other subcritical shear flows. Remarkably, the flow properties of DRW persist even as the Reynolds number is increased beyond the linear stability threshold of the base flow. Simulations in a narrow parallelogram domain stretched in the azimuthal direction to revolve around the apparatus a full turn confirm that self-sustained vortices eventually concentrate into a localised pattern. The resulting statistical steady state satisfactorily reproduces qualitatively, and to a certain degree also quantitatively, the topology and properties of spiral turbulence as calculated in a large periodic domain of sufficient aspect ratio that is representative of the real system."}],"acknowledgement":"K.D.’s research was supported by an Australian Research Council Discovery Early Career\r\nResearcher Award (DE170100171). B.W., R.A., F.M. and A.M. research was supported by the Spanish Ministerio de Economía y Competitivdad (grant numbers FIS2016-77849-R and FIS2017-85794-P) and Ministerio de Ciencia e Innovación (grant number PID2020-114043GB-I00) and the Generalitat de Catalunya (grant 2017-SGR-785). B.W.’s research was also supported by the Chinese Scholarship Council (grant CSC no. 201806440152).","_id":"12137"},{"article_number":"A24","article_type":"original","isi":1,"date_created":"2021-02-28T23:01:25Z","abstract":[{"lang":"eng","text":"In this paper we experimentally study the transitional range of Reynolds numbers in\r\nplane Couette–Poiseuille flow, focusing our attention on the localized turbulent structures\r\ntriggered by a strong impulsive jet and the large-scale flow generated around these\r\nstructures. We present a detailed investigation of the large-scale flow and show how\r\nits amplitude depends on Reynolds number and amplitude perturbation. In addition,\r\nwe characterize the initial dynamics of the localized turbulent spot, which includes the\r\ncoupling between the small and large scales, as well as the dependence of the advection\r\nspeed on the large-scale flow generated around the spot. Finally, we provide the first\r\nexperimental measurements of the large-scale flow around an oblique turbulent band."}],"acknowledgement":"We thank Y. Duguet, S. Gomé, G. Lemoult, T. Liu, B. Semin and L.S. Tuckerman for\r\nfruitful discussions. \r\nThis work was supported by a grant, TRANSFLOW, provided by the Agence Nationale de\r\nla Recherche (ANR). A.M.P. was partially supported by the French Embassy in Russia (I.I. Mechnikov scholarship) and by the Russian Science Foundation (project no. 18-79-00189). L.K. was partially supported by the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement no. 754411.","quality_controlled":"1","_id":"9207","year":"2021","date_updated":"2025-04-14T07:43:51Z","department":[{"_id":"BjHo"}],"article_processing_charge":"Yes (via OA deal)","citation":{"ista":"Klotz L, Pavlenko AM, Wesfreid JE. 2021. Experimental measurements in plane Couette-Poiseuille flow: Dynamics of the large- and small-scale flow. Journal of Fluid Mechanics. 912, A24.","ama":"Klotz L, Pavlenko AM, Wesfreid JE. Experimental measurements in plane Couette-Poiseuille flow: Dynamics of the large- and small-scale flow. <i>Journal of Fluid Mechanics</i>. 2021;912. doi:<a href=\"https://doi.org/10.1017/jfm.2020.1089\">10.1017/jfm.2020.1089</a>","mla":"Klotz, Lukasz, et al. “Experimental Measurements in Plane Couette-Poiseuille Flow: Dynamics of the Large- and Small-Scale Flow.” <i>Journal of Fluid Mechanics</i>, vol. 912, A24, Cambridge University Press, 2021, doi:<a href=\"https://doi.org/10.1017/jfm.2020.1089\">10.1017/jfm.2020.1089</a>.","chicago":"Klotz, Lukasz, A. M. Pavlenko, and J. E. Wesfreid. “Experimental Measurements in Plane Couette-Poiseuille Flow: Dynamics of the Large- and Small-Scale Flow.” <i>Journal of Fluid Mechanics</i>. Cambridge University Press, 2021. <a href=\"https://doi.org/10.1017/jfm.2020.1089\">https://doi.org/10.1017/jfm.2020.1089</a>.","ieee":"L. Klotz, A. M. Pavlenko, and J. E. Wesfreid, “Experimental measurements in plane Couette-Poiseuille flow: Dynamics of the large- and small-scale flow,” <i>Journal of Fluid Mechanics</i>, vol. 912. Cambridge University Press, 2021.","apa":"Klotz, L., Pavlenko, A. M., &#38; Wesfreid, J. E. (2021). Experimental measurements in plane Couette-Poiseuille flow: Dynamics of the large- and small-scale flow. <i>Journal of Fluid Mechanics</i>. Cambridge University Press. <a href=\"https://doi.org/10.1017/jfm.2020.1089\">https://doi.org/10.1017/jfm.2020.1089</a>","short":"L. Klotz, A.M. Pavlenko, J.E. Wesfreid, Journal of Fluid Mechanics 912 (2021)."},"publication_identifier":{"issn":["0022-1120"],"eissn":["1469-7645"]},"oa":1,"day":"15","oa_version":"Published Version","intvolume":"       912","status":"public","tmp":{"image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","short":"CC BY (4.0)","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)"},"publication_status":"published","volume":912,"ddc":["530"],"language":[{"iso":"eng"}],"author":[{"id":"2C9AF1C2-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0003-1740-7635","last_name":"Klotz","full_name":"Klotz, Lukasz","first_name":"Lukasz"},{"last_name":"Pavlenko","full_name":"Pavlenko, A. M.","first_name":"A. M."},{"first_name":"J. E.","full_name":"Wesfreid, J. E.","last_name":"Wesfreid"}],"ec_funded":1,"publisher":"Cambridge University Press","date_published":"2021-02-15T00:00:00Z","title":"Experimental measurements in plane Couette-Poiseuille flow: Dynamics of the large- and small-scale flow","type":"journal_article","has_accepted_license":"1","month":"02","scopus_import":"1","project":[{"name":"ISTplus - Postdoctoral Fellowships","grant_number":"754411","_id":"260C2330-B435-11E9-9278-68D0E5697425","call_identifier":"H2020"}],"user_id":"4359f0d1-fa6c-11eb-b949-802e58b17ae8","publication":"Journal of Fluid Mechanics","doi":"10.1017/jfm.2020.1089","external_id":{"isi":["000618034400001"]},"file_date_updated":"2021-03-03T09:49:34Z","file":[{"date_created":"2021-03-03T09:49:34Z","creator":"dernst","access_level":"open_access","file_id":"9220","file_name":"2021_JourFluidMechanics_Klotz.pdf","date_updated":"2021-03-03T09:49:34Z","file_size":4124471,"content_type":"application/pdf","relation":"main_file","success":1,"checksum":"b8020d6338667673e34fde0608913dd2"}]},{"main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/2008.08851"}],"article_number":"A65","article_type":"original","isi":1,"arxiv":1,"date_created":"2021-03-28T22:01:42Z","acknowledgement":"We gratefully acknowledge Joran Rolland, Yohann Duguet, Romain Monchaux, S´ebastien Gom´e, Laurette Tuckerman, Dwight Barkley, Olivier Dauchot and Sabine Bottin for fruitful discussions. We thank Xavier Benoit-Gonin, Amaury Fourgeaud, Thierry Darnige, Olivier Brouard and Justine Laurent for technical help. This work has benefited from the ANR TransFlow, and by starting grants obtained by B.S. from CNRS (INSIS) and ESPCI. T.M. was\r\nsupported by a Joliot visiting professorship grant from ESPCI.","abstract":[{"text":"We report the results of an experimental investigation into the decay of turbulence in plane Couette–Poiseuille flow using ‘quench’ experiments where the flow laminarises after a sudden reduction in Reynolds number Re. Specifically, we study the velocity field in the streamwise–spanwise plane. We show that the spanwise velocity containing rolls decays faster than the streamwise velocity, which displays elongated regions of higher or lower velocity called streaks. At final Reynolds numbers above 425, the decay of streaks displays two stages: first a slow decay when rolls are present and secondly a more rapid decay of streaks alone. The difference in behaviour results from the regeneration of streaks by rolls, called the lift-up effect. We define the turbulent fraction as the portion of the flow containing turbulence and this is estimated by thresholding the spanwise velocity component. It decreases linearly with time in the whole range of final Re. The corresponding decay slope increases linearly with final Re. The extrapolated value at which this decay slope vanishes is Reaz≈656±10, close to Reg≈670 at which turbulence is self-sustained. The decay of the energy computed from the spanwise velocity component is found to be exponential. The corresponding decay rate increases linearly with Re, with an extrapolated vanishing value at ReAz≈688±10. This value is also close to the value at which the turbulence is self-sustained, showing that valuable information on the transition can be obtained over a wide range of Re.","lang":"eng"}],"quality_controlled":"1","_id":"9297","year":"2021","department":[{"_id":"BjHo"}],"date_updated":"2023-08-07T14:30:11Z","article_processing_charge":"No","citation":{"ieee":"T. Liu, B. Semin, L. Klotz, R. Godoy-Diana, J. E. Wesfreid, and T. Mullin, “Decay of streaks and rolls in plane Couette-Poiseuille flow,” <i>Journal of Fluid Mechanics</i>, vol. 915. Cambridge University Press, 2021.","chicago":"Liu, T., B. Semin, Lukasz Klotz, R. Godoy-Diana, J. E. Wesfreid, and T. Mullin. “Decay of Streaks and Rolls in Plane Couette-Poiseuille Flow.” <i>Journal of Fluid Mechanics</i>. Cambridge University Press, 2021. <a href=\"https://doi.org/10.1017/jfm.2021.89\">https://doi.org/10.1017/jfm.2021.89</a>.","apa":"Liu, T., Semin, B., Klotz, L., Godoy-Diana, R., Wesfreid, J. E., &#38; Mullin, T. (2021). Decay of streaks and rolls in plane Couette-Poiseuille flow. <i>Journal of Fluid Mechanics</i>. Cambridge University Press. <a href=\"https://doi.org/10.1017/jfm.2021.89\">https://doi.org/10.1017/jfm.2021.89</a>","short":"T. Liu, B. Semin, L. Klotz, R. Godoy-Diana, J.E. Wesfreid, T. Mullin, Journal of Fluid Mechanics 915 (2021).","ista":"Liu T, Semin B, Klotz L, Godoy-Diana R, Wesfreid JE, Mullin T. 2021. Decay of streaks and rolls in plane Couette-Poiseuille flow. Journal of Fluid Mechanics. 915, A65.","ama":"Liu T, Semin B, Klotz L, Godoy-Diana R, Wesfreid JE, Mullin T. Decay of streaks and rolls in plane Couette-Poiseuille flow. <i>Journal of Fluid Mechanics</i>. 2021;915. doi:<a href=\"https://doi.org/10.1017/jfm.2021.89\">10.1017/jfm.2021.89</a>","mla":"Liu, T., et al. “Decay of Streaks and Rolls in Plane Couette-Poiseuille Flow.” <i>Journal of Fluid Mechanics</i>, vol. 915, A65, Cambridge University Press, 2021, doi:<a href=\"https://doi.org/10.1017/jfm.2021.89\">10.1017/jfm.2021.89</a>."},"publication_identifier":{"issn":["0022-1120"],"eissn":["1469-7645"]},"oa":1,"day":"17","oa_version":"Preprint","intvolume":"       915","status":"public","publication_status":"published","volume":915,"language":[{"iso":"eng"}],"author":[{"full_name":"Liu, T.","first_name":"T.","last_name":"Liu"},{"full_name":"Semin, B.","first_name":"B.","last_name":"Semin"},{"full_name":"Klotz, Lukasz","first_name":"Lukasz","last_name":"Klotz","id":"2C9AF1C2-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0003-1740-7635"},{"last_name":"Godoy-Diana","full_name":"Godoy-Diana, R.","first_name":"R."},{"last_name":"Wesfreid","full_name":"Wesfreid, J. E.","first_name":"J. E."},{"last_name":"Mullin","first_name":"T.","full_name":"Mullin, T."}],"date_published":"2021-03-17T00:00:00Z","publisher":"Cambridge University Press","title":"Decay of streaks and rolls in plane Couette-Poiseuille flow","type":"journal_article","month":"03","scopus_import":"1","user_id":"4359f0d1-fa6c-11eb-b949-802e58b17ae8","publication":"Journal of Fluid Mechanics","external_id":{"arxiv":["2008.08851"],"isi":["000629677500001"]},"doi":"10.1017/jfm.2021.89"},{"title":"Suppression of turbulence and travelling waves in a vertical heated pipe","author":[{"id":"0BE7553A-1004-11EA-B805-18983DDC885E","orcid":"0000-0001-7173-4923","last_name":"Marensi","full_name":"Marensi, Elena","first_name":"Elena"},{"last_name":"He","full_name":"He, Shuisheng","first_name":"Shuisheng"},{"first_name":"Ashley P.","full_name":"Willis, Ashley P.","last_name":"Willis"}],"date_published":"2021-07-25T00:00:00Z","publisher":"Cambridge University Press","language":[{"iso":"eng"}],"volume":919,"ddc":["530"],"publication_status":"published","tmp":{"image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","short":"CC BY (4.0)","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)"},"intvolume":"       919","status":"public","file":[{"file_id":"9766","access_level":"open_access","date_updated":"2021-08-03T09:53:28Z","file_size":4087358,"file_name":"2021_JournalFluidMechanics_Marensi.pdf","relation":"main_file","success":1,"content_type":"application/pdf","checksum":"867ad077e45c181c2c5ec1311ba27c41","date_created":"2021-08-03T09:53:28Z","creator":"kschuh"}],"doi":"10.1017/jfm.2021.371","external_id":{"arxiv":["2008.13486"],"isi":["000653785000001"]},"file_date_updated":"2021-08-03T09:53:28Z","publication":"Journal of Fluid Mechanics","corr_author":"1","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","has_accepted_license":"1","month":"07","scopus_import":"1","type":"journal_article","year":"2021","department":[{"_id":"BjHo"}],"date_updated":"2025-07-10T12:01:47Z","_id":"9467","abstract":[{"text":"Turbulence in the flow of fluid through a pipe can be suppressed by buoyancy forces. As the suppression of turbulence leads to severe heat transfer deterioration, this is an important and undesirable phenomenon in both heating and cooling applications. Vertical flow is often considered, as the axial buoyancy force can help drive the flow. With heating measured by the buoyancy parameter 𝐶, our direct numerical simulations show that shear-driven turbulence may either be completely laminarised or it transitions to a relatively quiescent convection-driven state. Buoyancy forces cause a flattening of the base flow profile, which in isothermal pipe flow has recently been linked to complete suppression of turbulence (Kühnen et al., Nat. Phys., vol. 14, 2018, pp. 386–390), and the flattened laminar base profile has enhanced nonlinear stability (Marensi et al., J. Fluid Mech., vol. 863, 2019, pp. 50–875). In agreement with these findings, the nonlinear lower-branch travelling-wave solution analysed here, which is believed to mediate transition to turbulence in isothermal pipe flow, is shown to be suppressed by buoyancy. A linear instability of the laminar base flow is responsible for the appearance of the relatively quiescent convection driven state for 𝐶≳4 across the range of Reynolds numbers considered. In the suppression of turbulence, however, i.e. in the transition from turbulence, we find clearer association with the analysis of He et al. (J. Fluid Mech., vol. 809, 2016, pp. 31–71) than with the above dynamical systems approach, which describes better the transition to turbulence. The laminarisation criterion He et al. propose, based on an apparent Reynolds number of the flow as measured by its driving pressure gradient, is found to capture the critical 𝐶=𝐶𝑐𝑟(𝑅𝑒) above which the flow will be laminarised or switch to the convection-driven type. Our analysis suggests that it is the weakened rolls, rather than the streaks, which appear to be critical for laminarisation.","lang":"eng"}],"acknowledgement":"The anonymous referees are kindly acknowledged for their useful suggestions andcomments.","quality_controlled":"1","date_created":"2021-06-06T22:01:30Z","arxiv":1,"article_type":"original","isi":1,"article_number":"A17","day":"25","oa_version":"Published Version","oa":1,"publication_identifier":{"eissn":["1469-7645"],"issn":["0022-1120"]},"citation":{"short":"E. Marensi, S. He, A.P. Willis, Journal of Fluid Mechanics 919 (2021).","apa":"Marensi, E., He, S., &#38; Willis, A. P. (2021). Suppression of turbulence and travelling waves in a vertical heated pipe. <i>Journal of Fluid Mechanics</i>. Cambridge University Press. <a href=\"https://doi.org/10.1017/jfm.2021.371\">https://doi.org/10.1017/jfm.2021.371</a>","chicago":"Marensi, Elena, Shuisheng He, and Ashley P. Willis. “Suppression of Turbulence and Travelling Waves in a Vertical Heated Pipe.” <i>Journal of Fluid Mechanics</i>. Cambridge University Press, 2021. <a href=\"https://doi.org/10.1017/jfm.2021.371\">https://doi.org/10.1017/jfm.2021.371</a>.","ieee":"E. Marensi, S. He, and A. P. Willis, “Suppression of turbulence and travelling waves in a vertical heated pipe,” <i>Journal of Fluid Mechanics</i>, vol. 919. Cambridge University Press, 2021.","mla":"Marensi, Elena, et al. “Suppression of Turbulence and Travelling Waves in a Vertical Heated Pipe.” <i>Journal of Fluid Mechanics</i>, vol. 919, A17, Cambridge University Press, 2021, doi:<a href=\"https://doi.org/10.1017/jfm.2021.371\">10.1017/jfm.2021.371</a>.","ama":"Marensi E, He S, Willis AP. Suppression of turbulence and travelling waves in a vertical heated pipe. <i>Journal of Fluid Mechanics</i>. 2021;919. doi:<a href=\"https://doi.org/10.1017/jfm.2021.371\">10.1017/jfm.2021.371</a>","ista":"Marensi E, He S, Willis AP. 2021. Suppression of turbulence and travelling waves in a vertical heated pipe. Journal of Fluid Mechanics. 919, A17."},"article_processing_charge":"Yes (via OA deal)"},{"date_created":"2020-06-29T07:59:35Z","isi":1,"article_type":"original","article_number":"A7","date_updated":"2025-07-10T11:55:03Z","department":[{"_id":"BjHo"}],"year":"2020","_id":"8043","quality_controlled":"1","acknowledgement":"The authors thank S. Zammert and B. Budanur for useful discussions. J. F. Gibson is gratefully acknowledged for the development and the maintenance of the code Channelflow. Y.D. would like to thank P. Schlatter and D. S. Henningson for an early collaboration on a similar topic in the case of plane Couette flow during the years 2008–2013.","abstract":[{"lang":"eng","text":"With decreasing Reynolds number, Re, turbulence in channel flow becomes spatio-temporally intermittent and self-organises into solitary stripes oblique to the mean flow direction. We report here the existence of localised nonlinear travelling wave solutions of the Navier–Stokes equations possessing this obliqueness property. Such solutions are identified numerically using edge tracking coupled with arclength continuation. All solutions emerge in saddle-node bifurcations at values of Re lower than the non-localised solutions. Relative periodic orbit solutions bifurcating from branches of travelling waves have also been computed. A complete parametric study is performed, including their stability, the investigation of their large-scale flow, and the robustness to changes of the numerical domain."}],"publication_identifier":{"issn":["0022-1120"],"eissn":["1469-7645"]},"citation":{"mla":"Paranjape, Chaitanya S., et al. “Oblique Stripe Solutions of Channel Flow.” <i>Journal of Fluid Mechanics</i>, vol. 897, A7, Cambridge University Press, 2020, doi:<a href=\"https://doi.org/10.1017/jfm.2020.322\">10.1017/jfm.2020.322</a>.","ama":"Paranjape CS, Duguet Y, Hof B. Oblique stripe solutions of channel flow. <i>Journal of Fluid Mechanics</i>. 2020;897. doi:<a href=\"https://doi.org/10.1017/jfm.2020.322\">10.1017/jfm.2020.322</a>","ista":"Paranjape CS, Duguet Y, Hof B. 2020. Oblique stripe solutions of channel flow. Journal of Fluid Mechanics. 897, A7.","apa":"Paranjape, C. S., Duguet, Y., &#38; Hof, B. (2020). Oblique stripe solutions of channel flow. <i>Journal of Fluid Mechanics</i>. Cambridge University Press. <a href=\"https://doi.org/10.1017/jfm.2020.322\">https://doi.org/10.1017/jfm.2020.322</a>","short":"C.S. Paranjape, Y. Duguet, B. Hof, Journal of Fluid Mechanics 897 (2020).","ieee":"C. S. Paranjape, Y. Duguet, and B. Hof, “Oblique stripe solutions of channel flow,” <i>Journal of Fluid Mechanics</i>, vol. 897. Cambridge University Press, 2020.","chicago":"Paranjape, Chaitanya S, Yohann Duguet, and Björn Hof. “Oblique Stripe Solutions of Channel Flow.” <i>Journal of Fluid Mechanics</i>. Cambridge University Press, 2020. <a href=\"https://doi.org/10.1017/jfm.2020.322\">https://doi.org/10.1017/jfm.2020.322</a>."},"article_processing_charge":"Yes (via OA deal)","day":"25","oa_version":"Published Version","oa":1,"volume":897,"ddc":["530"],"publication_status":"published","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by-nc-sa/4.0/legalcode","image":"/images/cc_by_nc_sa.png","name":"Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)","short":"CC BY-NC-SA (4.0)"},"status":"public","intvolume":"       897","title":"Oblique stripe solutions of channel flow","date_published":"2020-08-25T00:00:00Z","publisher":"Cambridge University Press","author":[{"id":"3D85B7C4-F248-11E8-B48F-1D18A9856A87","full_name":"Paranjape, Chaitanya S","first_name":"Chaitanya S","last_name":"Paranjape"},{"last_name":"Duguet","full_name":"Duguet, Yohann","first_name":"Yohann"},{"last_name":"Hof","full_name":"Hof, Björn","first_name":"Björn","id":"3A374330-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0003-2057-2754"}],"language":[{"iso":"eng"}],"corr_author":"1","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","scopus_import":"1","has_accepted_license":"1","month":"08","type":"journal_article","file":[{"date_created":"2020-06-30T08:37:37Z","creator":"cziletti","date_updated":"2020-07-14T12:48:08Z","file_size":767873,"file_name":"2020_JournalOfFluidMech_Paranjape.pdf","file_id":"8070","access_level":"open_access","checksum":"3f487bf6d9286787096306eaa18702e8","relation":"main_file","content_type":"application/pdf"}],"file_date_updated":"2020-07-14T12:48:08Z","doi":"10.1017/jfm.2020.322","external_id":{"isi":["000539132300001"]},"publication":"Journal of Fluid Mechanics"},{"oa":1,"oa_version":"Preprint","day":"10","article_processing_charge":"No","citation":{"chicago":"Lopez Alonso, Jose M, George H Choueiri, and Björn Hof. “Dynamics of Viscoelastic Pipe Flow at Low Reynolds Numbers in the Maximum Drag Reduction Limit.” <i>Journal of Fluid Mechanics</i>. Cambridge University Press, 2019. <a href=\"https://doi.org/10.1017/jfm.2019.486\">https://doi.org/10.1017/jfm.2019.486</a>.","ieee":"J. M. Lopez Alonso, G. H. Choueiri, and B. Hof, “Dynamics of viscoelastic pipe flow at low Reynolds numbers in the maximum drag reduction limit,” <i>Journal of Fluid Mechanics</i>, vol. 874. Cambridge University Press, pp. 699–719, 2019.","apa":"Lopez Alonso, J. M., Choueiri, G. H., &#38; Hof, B. (2019). Dynamics of viscoelastic pipe flow at low Reynolds numbers in the maximum drag reduction limit. <i>Journal of Fluid Mechanics</i>. Cambridge University Press. <a href=\"https://doi.org/10.1017/jfm.2019.486\">https://doi.org/10.1017/jfm.2019.486</a>","short":"J.M. Lopez Alonso, G.H. Choueiri, B. Hof, Journal of Fluid Mechanics 874 (2019) 699–719.","ista":"Lopez Alonso JM, Choueiri GH, Hof B. 2019. Dynamics of viscoelastic pipe flow at low Reynolds numbers in the maximum drag reduction limit. Journal of Fluid Mechanics. 874, 699–719.","ama":"Lopez Alonso JM, Choueiri GH, Hof B. Dynamics of viscoelastic pipe flow at low Reynolds numbers in the maximum drag reduction limit. <i>Journal of Fluid Mechanics</i>. 2019;874:699-719. doi:<a href=\"https://doi.org/10.1017/jfm.2019.486\">10.1017/jfm.2019.486</a>","mla":"Lopez Alonso, Jose M., et al. “Dynamics of Viscoelastic Pipe Flow at Low Reynolds Numbers in the Maximum Drag Reduction Limit.” <i>Journal of Fluid Mechanics</i>, vol. 874, Cambridge University Press, 2019, pp. 699–719, doi:<a href=\"https://doi.org/10.1017/jfm.2019.486\">10.1017/jfm.2019.486</a>."},"publication_identifier":{"eissn":["1469-7645"],"issn":["0022-1120"]},"abstract":[{"text":"Polymer additives can substantially reduce the drag of turbulent flows and the upperlimit, the so called “maximum drag reduction” (MDR) asymptote is universal, i.e. inde-pendent of the type of polymer and solvent used. Until recently, the consensus was that,in this limit, flows are in a marginal state where only a minimal level of turbulence activ-ity persists. Observations in direct numerical simulations using minimal sized channelsappeared  to  support  this  view  and  reported  long  “hibernation”  periods  where  turbu-lence is marginalized. In simulations of pipe flow we find that, indeed, with increasingWeissenberg number (Wi), turbulence expresses long periods of hibernation if the domainsize is small. However, with increasing pipe length, the temporal hibernation continuouslyalters to spatio-temporal intermittency and here the flow consists of turbulent puffs sur-rounded by laminar flow. Moreover, upon an increase in Wi, the flow fully relaminarises,in agreement with recent experiments. At even larger Wi, a different instability is en-countered causing a drag increase towards MDR. Our findings hence link earlier minimalflow unit simulations with recent experiments and confirm that the addition of polymersinitially suppresses Newtonian turbulence and leads to a reverse transition. The MDRstate on the other hand results from a separate instability and the underlying dynamicscorresponds to the recently proposed state of elasto-inertial-turbulence (EIT).","lang":"eng"}],"quality_controlled":"1","_id":"7397","year":"2019","department":[{"_id":"BjHo"}],"date_updated":"2025-05-14T11:21:59Z","main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/1808.04080"}],"article_type":"original","isi":1,"arxiv":1,"date_created":"2020-01-29T16:05:19Z","publication":"Journal of Fluid Mechanics","doi":"10.1017/jfm.2019.486","external_id":{"arxiv":["1808.04080"],"isi":["000475349900001"]},"type":"journal_article","month":"09","scopus_import":"1","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","language":[{"iso":"eng"}],"author":[{"first_name":"Jose M","full_name":"Lopez Alonso, Jose M","last_name":"Lopez Alonso","id":"40770848-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0002-0384-2022"},{"id":"448BD5BC-F248-11E8-B48F-1D18A9856A87","last_name":"Choueiri","first_name":"George H","full_name":"Choueiri, George H"},{"full_name":"Hof, Björn","first_name":"Björn","last_name":"Hof","orcid":"0000-0003-2057-2754","id":"3A374330-F248-11E8-B48F-1D18A9856A87"}],"date_published":"2019-09-10T00:00:00Z","publisher":"Cambridge University Press","title":"Dynamics of viscoelastic pipe flow at low Reynolds numbers in the maximum drag reduction limit","intvolume":"       874","status":"public","publication_status":"published","volume":874,"page":"699-719"},{"intvolume":"       867","status":"public","publication_status":"published","volume":867,"page":"934-948","language":[{"iso":"eng"}],"ec_funded":1,"author":[{"first_name":"Davide","full_name":"Scarselli, Davide","last_name":"Scarselli","orcid":"0000-0001-5227-4271","id":"40315C30-F248-11E8-B48F-1D18A9856A87"},{"id":"3A47AE32-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0003-4312-0179","last_name":"Kühnen","first_name":"Jakob","full_name":"Kühnen, Jakob"},{"first_name":"Björn","full_name":"Hof, Björn","last_name":"Hof","orcid":"0000-0003-2057-2754","id":"3A374330-F248-11E8-B48F-1D18A9856A87"}],"date_published":"2019-05-25T00:00:00Z","publisher":"Cambridge University Press","title":"Relaminarising pipe flow by wall movement","type":"journal_article","month":"05","scopus_import":"1","project":[{"_id":"25152F3A-B435-11E9-9278-68D0E5697425","name":"Decoding the complexity of turbulence at its origin","grant_number":"306589","call_identifier":"FP7"},{"call_identifier":"H2020","name":"Eliminating turbulence in oil pipelines","grant_number":"737549","_id":"25104D44-B435-11E9-9278-68D0E5697425"}],"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","publication":"Journal of Fluid Mechanics","external_id":{"arxiv":["1807.05357"],"isi":["000462606100001"]},"doi":"10.1017/jfm.2019.191","main_file_link":[{"url":"https://arxiv.org/abs/1807.05357","open_access":"1"}],"isi":1,"arxiv":1,"date_created":"2019-04-07T21:59:14Z","abstract":[{"lang":"eng","text":"Following  the  recent  observation  that  turbulent  pipe  flow  can  be  relaminarised  bya  relatively  simple  modification  of  the  mean  velocity  profile,  we  here  carry  out  aquantitative  experimental  investigation  of  this  phenomenon.  Our  study  confirms  thata  flat  velocity  profile  leads  to  a  collapse  of  turbulence  and  in  order  to  achieve  theblunted  profile  shape,  we  employ  a  moving  pipe  segment  that  is  briefly  and  rapidlyshifted  in  the  streamwise  direction.  The  relaminarisation  threshold  and  the  minimumshift  length  and  speeds  are  determined  as  a  function  of  Reynolds  number.  Althoughturbulence  is  still  active  after  the  acceleration  phase,  the  modulated  profile  possessesa  severely  decreased  lift-up  potential  as  measured  by  transient  growth.  As  shown,this  results  in  an  exponential  decay  of  fluctuations  and  the  flow  relaminarises.  Whilethis  method  can  be  easily  applied  at  low  to  moderate  flow  speeds,  the  minimumstreamwise  length  over  which  the  acceleration  needs  to  act  increases  linearly  with  theReynolds  number."}],"quality_controlled":"1","_id":"6228","related_material":{"link":[{"relation":"supplementary_material","url":"https://doi.org/10.1017/jfm.2019.191"}],"record":[{"relation":"dissertation_contains","id":"7258","status":"public"}]},"year":"2019","date_updated":"2026-07-15T22:31:08Z","department":[{"_id":"BjHo"}],"article_processing_charge":"No","citation":{"ieee":"D. Scarselli, J. Kühnen, and B. Hof, “Relaminarising pipe flow by wall movement,” <i>Journal of Fluid Mechanics</i>, vol. 867. Cambridge University Press, pp. 934–948, 2019.","chicago":"Scarselli, Davide, Jakob Kühnen, and Björn Hof. “Relaminarising Pipe Flow by Wall Movement.” <i>Journal of Fluid Mechanics</i>. Cambridge University Press, 2019. <a href=\"https://doi.org/10.1017/jfm.2019.191\">https://doi.org/10.1017/jfm.2019.191</a>.","short":"D. Scarselli, J. Kühnen, B. Hof, Journal of Fluid Mechanics 867 (2019) 934–948.","apa":"Scarselli, D., Kühnen, J., &#38; Hof, B. (2019). Relaminarising pipe flow by wall movement. <i>Journal of Fluid Mechanics</i>. Cambridge University Press. <a href=\"https://doi.org/10.1017/jfm.2019.191\">https://doi.org/10.1017/jfm.2019.191</a>","ista":"Scarselli D, Kühnen J, Hof B. 2019. Relaminarising pipe flow by wall movement. Journal of Fluid Mechanics. 867, 934–948.","ama":"Scarselli D, Kühnen J, Hof B. Relaminarising pipe flow by wall movement. <i>Journal of Fluid Mechanics</i>. 2019;867:934-948. doi:<a href=\"https://doi.org/10.1017/jfm.2019.191\">10.1017/jfm.2019.191</a>","mla":"Scarselli, Davide, et al. “Relaminarising Pipe Flow by Wall Movement.” <i>Journal of Fluid Mechanics</i>, vol. 867, Cambridge University Press, 2019, pp. 934–48, doi:<a href=\"https://doi.org/10.1017/jfm.2019.191\">10.1017/jfm.2019.191</a>."},"publication_identifier":{"issn":["0022-1120"],"eissn":["1469-7645"]},"oa":1,"oa_version":"Preprint","day":"25"},{"doi":"10.1017/jfm.2017.923","external_id":{"isi":["000437858300003"],"arxiv":["1709.06372"]},"publication":"Journal of Fluid Mechanics","user_id":"c635000d-4b10-11ee-a964-aac5a93f6ac1","month":"03","project":[{"call_identifier":"FP7","_id":"25152F3A-B435-11E9-9278-68D0E5697425","name":"Decoding the complexity of turbulence at its origin","grant_number":"306589"}],"scopus_import":"1","type":"journal_article","title":"The critical point of the transition to turbulence in pipe flow","author":[{"id":"3C5A959A-F248-11E8-B48F-1D18A9856A87","last_name":"Vasudevan","full_name":"Vasudevan, Mukund","first_name":"Mukund"},{"orcid":"0000-0003-2057-2754","id":"3A374330-F248-11E8-B48F-1D18A9856A87","last_name":"Hof","full_name":"Hof, Björn","first_name":"Björn"}],"ec_funded":1,"publisher":"Cambridge University Press","date_published":"2018-03-25T00:00:00Z","language":[{"iso":"eng"}],"volume":839,"page":"76-94","publication_status":"published","intvolume":"       839","status":"public","day":"25","oa_version":"Preprint","oa":1,"publication_identifier":{"eissn":["1469-7645"],"issn":["0022-1120"]},"citation":{"ista":"Vasudevan M, Hof B. 2018. The critical point of the transition to turbulence in pipe flow. Journal of Fluid Mechanics. 839, 76–94.","ama":"Vasudevan M, Hof B. The critical point of the transition to turbulence in pipe flow. <i>Journal of Fluid Mechanics</i>. 2018;839:76-94. doi:<a href=\"https://doi.org/10.1017/jfm.2017.923\">10.1017/jfm.2017.923</a>","mla":"Vasudevan, Mukund, and Björn Hof. “The Critical Point of the Transition to Turbulence in Pipe Flow.” <i>Journal of Fluid Mechanics</i>, vol. 839, Cambridge University Press, 2018, pp. 76–94, doi:<a href=\"https://doi.org/10.1017/jfm.2017.923\">10.1017/jfm.2017.923</a>.","ieee":"M. Vasudevan and B. Hof, “The critical point of the transition to turbulence in pipe flow,” <i>Journal of Fluid Mechanics</i>, vol. 839. Cambridge University Press, pp. 76–94, 2018.","chicago":"Vasudevan, Mukund, and Björn Hof. “The Critical Point of the Transition to Turbulence in Pipe Flow.” <i>Journal of Fluid Mechanics</i>. Cambridge University Press, 2018. <a href=\"https://doi.org/10.1017/jfm.2017.923\">https://doi.org/10.1017/jfm.2017.923</a>.","apa":"Vasudevan, M., &#38; Hof, B. (2018). The critical point of the transition to turbulence in pipe flow. <i>Journal of Fluid Mechanics</i>. Cambridge University Press. <a href=\"https://doi.org/10.1017/jfm.2017.923\">https://doi.org/10.1017/jfm.2017.923</a>","short":"M. Vasudevan, B. Hof, Journal of Fluid Mechanics 839 (2018) 76–94."},"article_processing_charge":"No","year":"2018","department":[{"_id":"BjHo"}],"date_updated":"2025-04-14T13:36:56Z","_id":"5996","abstract":[{"text":"In pipes, turbulence sets in despite the linear stability of the laminar Hagen–Poiseuille flow. The Reynolds number ( ) for which turbulence first appears in a given experiment – the ‘natural transition point’ – depends on imperfections of the set-up, or, more precisely, on the magnitude of finite amplitude perturbations. At onset, turbulence typically only occupies a certain fraction of the flow, and this fraction equally is found to differ from experiment to experiment. Despite these findings, Reynolds proposed that after sufficiently long times, flows may settle to steady conditions: below a critical velocity, flows should (regardless of initial conditions) always return to laminar, while above this velocity, eddying motion should persist. As will be shown, even in pipes several thousand diameters long, the spatio-temporal intermittent flow patterns observed at the end of the pipe strongly depend on the initial conditions, and there is no indication that different flow patterns would eventually settle to a (statistical) steady state. Exploiting the fact that turbulent puffs do not age (i.e. they are memoryless), we continuously recreate the puff sequence exiting the pipe at the pipe entrance, and in doing so introduce periodic boundary conditions for the puff pattern. This procedure allows us to study the evolution of the flow patterns for arbitrary long times, and we find that after times in excess of advective time units, indeed a statistical steady state is reached. Although the resulting flows remain spatio-temporally intermittent, puff splitting and decay rates eventually reach a balance, so that the turbulent fraction fluctuates around a well-defined level which only depends on . In accordance with Reynolds’ proposition, we find that at lower (here 2020), flows eventually always resume to laminar, while for higher ( ), turbulence persists. The critical point for pipe flow hence falls in the interval of $2020 , which is in very good agreement with the recently proposed value of . The latter estimate was based on single-puff statistics and entirely neglected puff interactions. Unlike in typical contact processes where such interactions strongly affect the percolation threshold, in pipe flow, the critical point is only marginally influenced. Interactions, on the other hand, are responsible for the approach to the statistical steady state. As shown, they strongly affect the resulting flow patterns, where they cause ‘puff clustering’, and these regions of large puff densities are observed to travel across the puff pattern in a wave-like fashion.","lang":"eng"}],"acknowledgement":" We  also  thank  Philipp  Maier  and  the  IST  Austria  workshop  for  theirdedicated technical support","quality_controlled":"1","date_created":"2019-02-14T12:50:50Z","arxiv":1,"article_type":"original","isi":1,"main_file_link":[{"url":"https://arxiv.org/abs/1709.06372","open_access":"1"}]},{"article_processing_charge":"No","citation":{"ieee":"B. Song, D. Barkley, B. Hof, and M. Avila, “Speed and structure of turbulent fronts in pipe flow,” <i>Journal of Fluid Mechanics</i>, vol. 813. Cambridge University Press, pp. 1045–1059, 2017.","chicago":"Song, Baofang, Dwight Barkley, Björn Hof, and Marc Avila. “Speed and Structure of Turbulent Fronts in Pipe Flow.” <i>Journal of Fluid Mechanics</i>. Cambridge University Press, 2017. <a href=\"https://doi.org/10.1017/jfm.2017.14\">https://doi.org/10.1017/jfm.2017.14</a>.","apa":"Song, B., Barkley, D., Hof, B., &#38; Avila, M. (2017). Speed and structure of turbulent fronts in pipe flow. <i>Journal of Fluid Mechanics</i>. Cambridge University Press. <a href=\"https://doi.org/10.1017/jfm.2017.14\">https://doi.org/10.1017/jfm.2017.14</a>","short":"B. Song, D. Barkley, B. Hof, M. Avila, Journal of Fluid Mechanics 813 (2017) 1045–1059.","ama":"Song B, Barkley D, Hof B, Avila M. Speed and structure of turbulent fronts in pipe flow. <i>Journal of Fluid Mechanics</i>. 2017;813:1045-1059. doi:<a href=\"https://doi.org/10.1017/jfm.2017.14\">10.1017/jfm.2017.14</a>","ista":"Song B, Barkley D, Hof B, Avila M. 2017. Speed and structure of turbulent fronts in pipe flow. Journal of Fluid Mechanics. 813, 1045–1059.","mla":"Song, Baofang, et al. “Speed and Structure of Turbulent Fronts in Pipe Flow.” <i>Journal of Fluid Mechanics</i>, vol. 813, Cambridge University Press, 2017, pp. 1045–59, doi:<a href=\"https://doi.org/10.1017/jfm.2017.14\">10.1017/jfm.2017.14</a>."},"publication_identifier":{"issn":["0022-1120"]},"oa":1,"day":"25","oa_version":"Submitted Version","main_file_link":[{"url":"https://arxiv.org/abs/1603.04077","open_access":"1"}],"isi":1,"arxiv":1,"date_created":"2018-12-11T11:50:04Z","quality_controlled":"1","abstract":[{"lang":"eng","text":"Using extensive direct numerical simulations, the dynamics of laminar-turbulent fronts in pipe flow is investigated for Reynolds numbers between and 5500. We here investigate the physical distinction between the fronts of weak and strong slugs both by analysing the turbulent kinetic energy budget and by comparing the downstream front motion to the advection speed of bulk turbulent structures. Our study shows that weak downstream fronts travel slower than turbulent structures in the bulk and correspond to decaying turbulence at the front. At the downstream front speed becomes faster than the advection speed, marking the onset of strong fronts. In contrast to weak fronts, turbulent eddies are generated at strong fronts by feeding on the downstream laminar flow. Our study also suggests that temporal fluctuations of production and dissipation at the downstream laminar-turbulent front drive the dynamical switches between the two types of front observed up to."}],"_id":"1087","department":[{"_id":"BjHo"}],"date_updated":"2025-06-04T08:35:11Z","year":"2017","publist_id":"6290","type":"journal_article","project":[{"call_identifier":"FP7","grant_number":"306589","_id":"25152F3A-B435-11E9-9278-68D0E5697425","name":"Decoding the complexity of turbulence at its origin"}],"scopus_import":"1","month":"02","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","publication":"Journal of Fluid Mechanics","doi":"10.1017/jfm.2017.14","external_id":{"arxiv":["1603.04077"],"isi":["000394376400044"]},"acknowledged_ssus":[{"_id":"ScienComp"}],"status":"public","intvolume":"       813","publication_status":"published","page":"1045 - 1059","volume":813,"language":[{"iso":"eng"}],"publisher":"Cambridge University Press","date_published":"2017-02-25T00:00:00Z","ec_funded":1,"author":[{"last_name":"Song","first_name":"Baofang","full_name":"Song, Baofang"},{"full_name":"Barkley, Dwight","first_name":"Dwight","last_name":"Barkley"},{"last_name":"Hof","full_name":"Hof, Björn","first_name":"Björn","id":"3A374330-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0003-2057-2754"},{"last_name":"Avila","first_name":"Marc","full_name":"Avila, Marc"}],"title":"Speed and structure of turbulent fronts in pipe flow"},{"year":"2017","department":[{"_id":"BjHo"}],"date_updated":"2025-06-04T08:10:13Z","_id":"1021","abstract":[{"lang":"eng","text":"Most flows in nature and engineering are turbulent because of their large velocities and spatial scales. Laboratory experiments on rotating quasi-Keplerian flows, for which the angular velocity decreases radially but the angular momentum increases, are however laminar at Reynolds numbers exceeding one million. This is in apparent contradiction to direct numerical simulations showing that in these experiments turbulence transition is triggered by the axial boundaries. We here show numerically that as the Reynolds number increases, turbulence becomes progressively confined to the boundary layers and the flow in the bulk fully relaminarizes. Our findings support that turbulence is unlikely to occur in isothermal constant-density quasi-Keplerian flows."}],"quality_controlled":"1","date_created":"2018-12-11T11:49:44Z","arxiv":1,"isi":1,"main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/1608.05527"}],"day":"25","oa_version":"Submitted Version","oa":1,"publication_identifier":{"issn":["0022-1120"]},"citation":{"mla":"Lopez Alonso, Jose M., and Marc Avila. “Boundary Layer Turbulence in Experiments on Quasi Keplerian Flows.” <i>Journal of Fluid Mechanics</i>, vol. 817, Cambridge University Press, 2017, pp. 21–34, doi:<a href=\"https://doi.org/10.1017/jfm.2017.109\">10.1017/jfm.2017.109</a>.","ama":"Lopez Alonso JM, Avila M. Boundary layer turbulence in experiments on quasi Keplerian flows. <i>Journal of Fluid Mechanics</i>. 2017;817:21-34. doi:<a href=\"https://doi.org/10.1017/jfm.2017.109\">10.1017/jfm.2017.109</a>","ista":"Lopez Alonso JM, Avila M. 2017. Boundary layer turbulence in experiments on quasi Keplerian flows. Journal of Fluid Mechanics. 817, 21–34.","apa":"Lopez Alonso, J. M., &#38; Avila, M. (2017). Boundary layer turbulence in experiments on quasi Keplerian flows. <i>Journal of Fluid Mechanics</i>. Cambridge University Press. <a href=\"https://doi.org/10.1017/jfm.2017.109\">https://doi.org/10.1017/jfm.2017.109</a>","short":"J.M. Lopez Alonso, M. Avila, Journal of Fluid Mechanics 817 (2017) 21–34.","chicago":"Lopez Alonso, Jose M, and Marc Avila. “Boundary Layer Turbulence in Experiments on Quasi Keplerian Flows.” <i>Journal of Fluid Mechanics</i>. Cambridge University Press, 2017. <a href=\"https://doi.org/10.1017/jfm.2017.109\">https://doi.org/10.1017/jfm.2017.109</a>.","ieee":"J. M. Lopez Alonso and M. Avila, “Boundary layer turbulence in experiments on quasi Keplerian flows,” <i>Journal of Fluid Mechanics</i>, vol. 817. Cambridge University Press, pp. 21–34, 2017."},"article_processing_charge":"No","title":"Boundary layer turbulence in experiments on quasi Keplerian flows","author":[{"full_name":"Lopez Alonso, Jose M","first_name":"Jose M","last_name":"Lopez Alonso","id":"40770848-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0002-0384-2022"},{"full_name":"Avila, Marc","first_name":"Marc","last_name":"Avila"}],"publisher":"Cambridge University Press","date_published":"2017-04-25T00:00:00Z","language":[{"iso":"eng"}],"page":"21 - 34","volume":817,"publication_status":"published","intvolume":"       817","status":"public","doi":"10.1017/jfm.2017.109","external_id":{"arxiv":["1608.05527"],"isi":["000398179100006"]},"publication":"Journal of Fluid Mechanics","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","month":"04","project":[{"name":"Information processing and computation in fish groups","grant_number":"RGP0065/2012","_id":"255008E4-B435-11E9-9278-68D0E5697425"}],"scopus_import":"1","type":"journal_article","publist_id":"6371"},{"title":"Relative periodic orbits form the backbone of turbulent pipe flow","date_published":"2017-12-25T00:00:00Z","publisher":"Cambridge University Press","author":[{"last_name":"Budanur","full_name":"Budanur, Nazmi B","first_name":"Nazmi B","id":"3EA1010E-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0003-0423-5010"},{"full_name":"Short, Kimberly","first_name":"Kimberly","last_name":"Short"},{"first_name":"Mohammad","full_name":"Farazmand, Mohammad","last_name":"Farazmand"},{"full_name":"Willis, Ashley","first_name":"Ashley","last_name":"Willis"},{"first_name":"Predrag","full_name":"Cvitanović, Predrag","last_name":"Cvitanović"}],"language":[{"iso":"eng"}],"page":"274 - 301","volume":833,"publication_status":"published","status":"public","intvolume":"       833","doi":"10.1017/jfm.2017.699","external_id":{"isi":["000414641700001"],"arxiv":["1705.03720"]},"publication":"Journal of Fluid Mechanics","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","project":[{"grant_number":"11-NSF-1070","_id":"25636330-B435-11E9-9278-68D0E5697425","name":"Genome-wide Analysis of Root Traits"}],"scopus_import":"1","month":"12","type":"journal_article","publist_id":"6862","department":[{"_id":"BjHo"}],"date_updated":"2025-06-04T09:45:57Z","year":"2017","_id":"792","quality_controlled":"1","abstract":[{"lang":"eng","text":"The chaotic dynamics of low-dimensional systems, such as Lorenz or Rössler flows, is guided by the infinity of periodic orbits embedded in their strange attractors. Whether this is also the case for the infinite-dimensional dynamics of Navier–Stokes equations has long been speculated, and is a topic of ongoing study. Periodic and relative periodic solutions have been shown to be involved in transitions to turbulence. Their relevance to turbulent dynamics – specifically, whether periodic orbits play the same role in high-dimensional nonlinear systems like the Navier–Stokes equations as they do in lower-dimensional systems – is the focus of the present investigation. We perform here a detailed study of pipe flow relative periodic orbits with energies and mean dissipations close to turbulent values. We outline several approaches to reduction of the translational symmetry of the system. We study pipe flow in a minimal computational cell at   Re=2500, and report a library of invariant solutions found with the aid of the method of slices. Detailed study of the unstable manifolds of a sample of these solutions is consistent with the picture that relative periodic orbits are embedded in the chaotic saddle and that they guide the turbulent dynamics."}],"date_created":"2018-12-11T11:48:32Z","arxiv":1,"isi":1,"main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/1705.03720"}],"day":"25","oa_version":"Submitted Version","oa":1,"publication_identifier":{"issn":["0022-1120"]},"citation":{"chicago":"Budanur, Nazmi B, Kimberly Short, Mohammad Farazmand, Ashley Willis, and Predrag Cvitanović. “Relative Periodic Orbits Form the Backbone of Turbulent Pipe Flow.” <i>Journal of Fluid Mechanics</i>. Cambridge University Press, 2017. <a href=\"https://doi.org/10.1017/jfm.2017.699\">https://doi.org/10.1017/jfm.2017.699</a>.","ieee":"N. B. Budanur, K. Short, M. Farazmand, A. Willis, and P. Cvitanović, “Relative periodic orbits form the backbone of turbulent pipe flow,” <i>Journal of Fluid Mechanics</i>, vol. 833. Cambridge University Press, pp. 274–301, 2017.","apa":"Budanur, N. B., Short, K., Farazmand, M., Willis, A., &#38; Cvitanović, P. (2017). Relative periodic orbits form the backbone of turbulent pipe flow. <i>Journal of Fluid Mechanics</i>. Cambridge University Press. <a href=\"https://doi.org/10.1017/jfm.2017.699\">https://doi.org/10.1017/jfm.2017.699</a>","short":"N.B. Budanur, K. Short, M. Farazmand, A. Willis, P. Cvitanović, Journal of Fluid Mechanics 833 (2017) 274–301.","ama":"Budanur NB, Short K, Farazmand M, Willis A, Cvitanović P. Relative periodic orbits form the backbone of turbulent pipe flow. <i>Journal of Fluid Mechanics</i>. 2017;833:274-301. doi:<a href=\"https://doi.org/10.1017/jfm.2017.699\">10.1017/jfm.2017.699</a>","ista":"Budanur NB, Short K, Farazmand M, Willis A, Cvitanović P. 2017. Relative periodic orbits form the backbone of turbulent pipe flow. Journal of Fluid Mechanics. 833, 274–301.","mla":"Budanur, Nazmi B., et al. “Relative Periodic Orbits Form the Backbone of Turbulent Pipe Flow.” <i>Journal of Fluid Mechanics</i>, vol. 833, Cambridge University Press, 2017, pp. 274–301, doi:<a href=\"https://doi.org/10.1017/jfm.2017.699\">10.1017/jfm.2017.699</a>."},"article_processing_charge":"No"},{"publisher":"Cambridge University Press","date_published":"2017-08-18T00:00:00Z","author":[{"id":"3EA1010E-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0003-0423-5010","full_name":"Budanur, Nazmi B","first_name":"Nazmi B","last_name":"Budanur"},{"id":"3A374330-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0003-2057-2754","last_name":"Hof","full_name":"Hof, Björn","first_name":"Björn"}],"title":"Heteroclinic path to spatially localized chaos in pipe flow","language":[{"iso":"eng"}],"publication_status":"published","volume":827,"status":"public","intvolume":"       827","publication":"Journal of Fluid Mechanics","external_id":{"arxiv":["1703.10484"],"isi":["000408326300001"]},"doi":"10.1017/jfm.2017.516","scopus_import":"1","month":"08","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","publist_id":"6824","type":"journal_article","date_updated":"2025-06-04T09:49:26Z","department":[{"_id":"BjHo"}],"year":"2017","quality_controlled":"1","abstract":[{"lang":"eng","text":"In shear flows at transitional Reynolds numbers, localized patches of turbulence, known as puffs, coexist with the laminar flow. Recently, Avila et al. (Phys. Rev. Lett., vol. 110, 2013, 224502) discovered two spatially localized relative periodic solutions for pipe flow, which appeared in a saddle-node bifurcation at low Reynolds number. Combining slicing methods for continuous symmetry reduction with Poincaré sections for the first time in a shear flow setting, we compute and visualize the unstable manifold of the lower-branch solution and show that it extends towards the neighbourhood of the upper-branch solution. Surprisingly, this connection even persists far above the bifurcation point and appears to mediate the first stage of the puff generation: amplification of streamwise localized fluctuations. When the state-space trajectories on the unstable manifold reach the vicinity of the upper branch, corresponding fluctuations expand in space and eventually take the usual shape of a puff."}],"_id":"824","arxiv":1,"date_created":"2018-12-11T11:48:42Z","main_file_link":[{"url":"https://arxiv.org/abs/1703.10484","open_access":"1"}],"article_number":"R1","isi":1,"oa_version":"Submitted Version","day":"18","oa":1,"publication_identifier":{"issn":["0022-1120"]},"article_processing_charge":"No","citation":{"short":"N.B. Budanur, B. Hof, Journal of Fluid Mechanics 827 (2017).","apa":"Budanur, N. B., &#38; Hof, B. (2017). Heteroclinic path to spatially localized chaos in pipe flow. <i>Journal of Fluid Mechanics</i>. Cambridge University Press. <a href=\"https://doi.org/10.1017/jfm.2017.516\">https://doi.org/10.1017/jfm.2017.516</a>","chicago":"Budanur, Nazmi B, and Björn Hof. “Heteroclinic Path to Spatially Localized Chaos in Pipe Flow.” <i>Journal of Fluid Mechanics</i>. Cambridge University Press, 2017. <a href=\"https://doi.org/10.1017/jfm.2017.516\">https://doi.org/10.1017/jfm.2017.516</a>.","ieee":"N. B. Budanur and B. Hof, “Heteroclinic path to spatially localized chaos in pipe flow,” <i>Journal of Fluid Mechanics</i>, vol. 827. Cambridge University Press, 2017.","mla":"Budanur, Nazmi B., and Björn Hof. “Heteroclinic Path to Spatially Localized Chaos in Pipe Flow.” <i>Journal of Fluid Mechanics</i>, vol. 827, R1, Cambridge University Press, 2017, doi:<a href=\"https://doi.org/10.1017/jfm.2017.516\">10.1017/jfm.2017.516</a>.","ista":"Budanur NB, Hof B. 2017. Heteroclinic path to spatially localized chaos in pipe flow. Journal of Fluid Mechanics. 827, R1.","ama":"Budanur NB, Hof B. Heteroclinic path to spatially localized chaos in pipe flow. <i>Journal of Fluid Mechanics</i>. 2017;827. doi:<a href=\"https://doi.org/10.1017/jfm.2017.516\">10.1017/jfm.2017.516</a>"}},{"corr_author":"1","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","month":"11","scopus_import":"1","project":[{"call_identifier":"FP7","name":"Decoding the complexity of turbulence at its origin","_id":"25152F3A-B435-11E9-9278-68D0E5697425","grant_number":"306589"}],"type":"journal_article","publist_id":"6922","external_id":{"arxiv":["1709.03738"],"isi":["000412934800005"]},"doi":"10.1017/jfm.2017.620","publication":"Journal of Fluid Mechanics","volume":831,"page":"418 - 432","publication_status":"published","intvolume":"       831","status":"public","title":"Transition to turbulence in pulsating pipe flow","author":[{"id":"3454D55E-F248-11E8-B48F-1D18A9856A87","last_name":"Xu","full_name":"Xu, Duo","first_name":"Duo"},{"first_name":"Sascha","full_name":"Warnecke, Sascha","last_name":"Warnecke"},{"first_name":"Baofang","full_name":"Song, Baofang","last_name":"Song"},{"id":"34BADBA6-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0002-0179-9737","last_name":"Ma","first_name":"Xingyu","full_name":"Ma, Xingyu"},{"orcid":"0000-0003-2057-2754","id":"3A374330-F248-11E8-B48F-1D18A9856A87","last_name":"Hof","full_name":"Hof, Björn","first_name":"Björn"}],"ec_funded":1,"publisher":"Cambridge University Press","date_published":"2017-11-25T00:00:00Z","language":[{"iso":"eng"}],"publication_identifier":{"issn":["0022-1120"]},"citation":{"mla":"Xu, Duo, et al. “Transition to Turbulence in Pulsating Pipe Flow.” <i>Journal of Fluid Mechanics</i>, vol. 831, Cambridge University Press, 2017, pp. 418–32, doi:<a href=\"https://doi.org/10.1017/jfm.2017.620\">10.1017/jfm.2017.620</a>.","ama":"Xu D, Warnecke S, Song B, Ma X, Hof B. Transition to turbulence in pulsating pipe flow. <i>Journal of Fluid Mechanics</i>. 2017;831:418-432. doi:<a href=\"https://doi.org/10.1017/jfm.2017.620\">10.1017/jfm.2017.620</a>","ista":"Xu D, Warnecke S, Song B, Ma X, Hof B. 2017. Transition to turbulence in pulsating pipe flow. Journal of Fluid Mechanics. 831, 418–432.","apa":"Xu, D., Warnecke, S., Song, B., Ma, X., &#38; Hof, B. (2017). Transition to turbulence in pulsating pipe flow. <i>Journal of Fluid Mechanics</i>. Cambridge University Press. <a href=\"https://doi.org/10.1017/jfm.2017.620\">https://doi.org/10.1017/jfm.2017.620</a>","short":"D. Xu, S. Warnecke, B. Song, X. Ma, B. Hof, Journal of Fluid Mechanics 831 (2017) 418–432.","chicago":"Xu, Duo, Sascha Warnecke, Baofang Song, Xingyu Ma, and Björn Hof. “Transition to Turbulence in Pulsating Pipe Flow.” <i>Journal of Fluid Mechanics</i>. Cambridge University Press, 2017. <a href=\"https://doi.org/10.1017/jfm.2017.620\">https://doi.org/10.1017/jfm.2017.620</a>.","ieee":"D. Xu, S. Warnecke, B. Song, X. Ma, and B. Hof, “Transition to turbulence in pulsating pipe flow,” <i>Journal of Fluid Mechanics</i>, vol. 831. Cambridge University Press, pp. 418–432, 2017."},"article_processing_charge":"No","day":"25","oa_version":"Submitted Version","oa":1,"date_created":"2018-12-11T11:48:17Z","arxiv":1,"isi":1,"main_file_link":[{"url":"https://arxiv.org/abs/1709.03738","open_access":"1"}],"year":"2017","department":[{"_id":"BjHo"}],"date_updated":"2025-06-04T09:44:06Z","_id":"745","abstract":[{"text":"Fluid flows in nature and applications are frequently subject to periodic velocity modulations. Surprisingly, even for the generic case of flow through a straight pipe, there is little consensus regarding the influence of pulsation on the transition threshold to turbulence: while most studies predict a monotonically increasing threshold with pulsation frequency (i.e. Womersley number, ), others observe a decreasing threshold for identical parameters and only observe an increasing threshold at low . In the present study we apply recent advances in the understanding of transition in steady shear flows to pulsating pipe flow. For moderate pulsation amplitudes we find that the first instability encountered is subcritical (i.e. requiring finite amplitude disturbances) and gives rise to localized patches of turbulence ('puffs') analogous to steady pipe flow. By monitoring the impact of pulsation on the lifetime of turbulence we map the onset of turbulence in parameter space. Transition in pulsatile flow can be separated into three regimes. At small Womersley numbers the dynamics is dominated by the decay turbulence suffers during the slower part of the cycle and hence transition is delayed significantly. As shown in this regime thresholds closely agree with estimates based on a quasi-steady flow assumption only taking puff decay rates into account. The transition point predicted in the zero limit equals to the critical point for steady pipe flow offset by the oscillation Reynolds number (i.e. the dimensionless oscillation amplitude). In the high frequency limit on the other hand, puff lifetimes are identical to those in steady pipe flow and hence the transition threshold appears to be unaffected by flow pulsation. In the intermediate frequency regime the transition threshold sharply drops (with increasing ) from the decay dominated (quasi-steady) threshold to the steady pipe flow level.","lang":"eng"}],"quality_controlled":"1"},{"day":"10","oa_version":"None","keyword":["mechanical engineering","mechanics of materials","condensed matter physics"],"oa":1,"publication_identifier":{"issn":["0022-1120","1469-7645"]},"citation":{"short":"O. Bühler, C.J. Muller, Journal of Fluid Mechanics 588 (2007) 1–28.","apa":"Bühler, O., &#38; Muller, C. J. (2007). Instability and focusing of internal tides in the deep ocean. <i>Journal of Fluid Mechanics</i>. Cambridge University Press. <a href=\"https://doi.org/10.1017/s0022112007007410\">https://doi.org/10.1017/s0022112007007410</a>","chicago":"Bühler, Oliver, and Caroline J Muller. “Instability and Focusing of Internal Tides in the Deep Ocean.” <i>Journal of Fluid Mechanics</i>. Cambridge University Press, 2007. <a href=\"https://doi.org/10.1017/s0022112007007410\">https://doi.org/10.1017/s0022112007007410</a>.","ieee":"O. Bühler and C. J. Muller, “Instability and focusing of internal tides in the deep ocean,” <i>Journal of Fluid Mechanics</i>, vol. 588. Cambridge University Press, pp. 1–28, 2007.","mla":"Bühler, Oliver, and Caroline J. Muller. “Instability and Focusing of Internal Tides in the Deep Ocean.” <i>Journal of Fluid Mechanics</i>, vol. 588, Cambridge University Press, 2007, pp. 1–28, doi:<a href=\"https://doi.org/10.1017/s0022112007007410\">10.1017/s0022112007007410</a>.","ama":"Bühler O, Muller CJ. Instability and focusing of internal tides in the deep ocean. <i>Journal of Fluid Mechanics</i>. 2007;588:1-28. doi:<a href=\"https://doi.org/10.1017/s0022112007007410\">10.1017/s0022112007007410</a>","ista":"Bühler O, Muller CJ. 2007. Instability and focusing of internal tides in the deep ocean. Journal of Fluid Mechanics. 588, 1–28."},"article_processing_charge":"No","year":"2007","date_updated":"2022-01-24T13:43:36Z","_id":"9149","abstract":[{"text":"The interaction of tidal currents with sea-floor topography results in the radiation of internal gravity waves into the ocean interior. These waves are called internal tides and their dissipation due to nonlinear wave breaking and concomitant three-dimensional turbulence could play an important role in the mixing of the abyssal ocean, and hence in controlling the large-scale ocean circulation.\r\nAs part of on-going work aimed at providing a theory for the vertical distribution of wave breaking over sea-floor topography, in this paper we investigate the instability of internal tides in a very simple linear model that helps us to relate the formation of unstable regions to simple features in the sea-floor topography. For two-dimensional tides over one-dimensional topography we find that the formation of overturning instabilities is closely linked to the singularities in the topography shape and that it is possible to have stable waves at the sea floor and unstable waves in the ocean interior above.\r\nFor three-dimensional tides over two-dimensional topography there is in addition an effect of geometric focusing of wave energy into localized regions of high wave amplitude, and we investigate this focusing effect in simple examples. Overall, we find that the distribution of unstable wave breaking regions can be highly non-uniform even for very simple idealized topography shapes.","lang":"eng"}],"quality_controlled":"1","date_created":"2021-02-15T14:41:45Z","article_type":"original","main_file_link":[{"open_access":"1","url":"https://doi.org/10.1017/S0022112007007410"}],"doi":"10.1017/s0022112007007410","publication":"Journal of Fluid Mechanics","user_id":"8b945eb4-e2f2-11eb-945a-df72226e66a9","month":"10","type":"journal_article","title":"Instability and focusing of internal tides in the deep ocean","author":[{"last_name":"Bühler","first_name":"Oliver","full_name":"Bühler, Oliver"},{"orcid":"0000-0001-5836-5350","id":"f978ccb0-3f7f-11eb-b193-b0e2bd13182b","full_name":"Muller, Caroline J","first_name":"Caroline J","last_name":"Muller"}],"date_published":"2007-10-10T00:00:00Z","publisher":"Cambridge University Press","language":[{"iso":"eng"}],"page":"1-28","volume":588,"extern":"1","publication_status":"published","intvolume":"       588","status":"public"}]