[{"publication_status":"epub_ahead","external_id":{"arxiv":["2311.11474"]},"department":[{"_id":"GradSch"},{"_id":"BjHo"}],"date_created":"2026-02-17T11:38:41Z","corr_author":"1","language":[{"iso":"eng"}],"quality_controlled":"1","abstract":[{"lang":"eng","text":"Depending on the type of flow, the transition to turbulence can take one of two forms: either turbulence arises from a sequence of instabilities or from the spatial proliferation of transiently chaotic domains, a process analogous to directed percolation. The former scenario is commonly referred to as a supercritical transition and frequently encountered in flows destabilized by body forces, whereas the latter subcritical transition is common in shear flows. Both cases are inherently continuous in a sense that the transformation from ordered laminar to fully turbulent fluid motion is only accomplished gradually with flow speed. Here we show that these established transition types do not account for the more general setting of shear flows subject to body forces. The combination of the two continuous scenarios leads to the attenuation of spatial coupling; with increasing forcing amplitude, the transition becomes increasingly sharp and eventually discontinuous. We argue that the suppression of laminar–turbulent coexistence and the approach towards a discontinuous phase transition potentially apply to a broad range of situations including flows subject to, for example, buoyancy, centrifugal or electromagnetic forces."}],"publication":"Nature Physics","scopus_import":"1","author":[{"full_name":"Yang, Bowen","last_name":"Yang","first_name":"Bowen","id":"71b6ff4b-15b2-11ec-abd3-aef6b028cf7e","orcid":"0000-0002-4843-6853"},{"id":"3677B57C-F248-11E8-B48F-1D18A9856A87","first_name":"Yi","full_name":"Zhuang, Yi","last_name":"Zhuang"},{"full_name":"Yalniz, Gökhan","last_name":"Yalniz","id":"66E74FA2-D8BF-11E9-8249-8DE2E5697425","first_name":"Gökhan","orcid":"0000-0002-8490-9312"},{"id":"3C5A959A-F248-11E8-B48F-1D18A9856A87","first_name":"Mukund","last_name":"Vasudevan","full_name":"Vasudevan, Mukund"},{"last_name":"Marensi","full_name":"Marensi, Elena","first_name":"Elena","id":"0BE7553A-1004-11EA-B805-18983DDC885E","orcid":"0000-0001-7173-4923"},{"first_name":"Björn","id":"3A374330-F248-11E8-B48F-1D18A9856A87","last_name":"Hof","full_name":"Hof, Björn","orcid":"0000-0003-2057-2754"}],"acknowledgement":"The work was supported by the Simons Foundation (grant number 662960, to B.H.). Open access funding provided by Institute of Science and Technology (IST Austria).","publication_identifier":{"eissn":["1745-2481"],"issn":["1745-2473"]},"arxiv":1,"ddc":["532"],"OA_place":"publisher","doi":"10.1038/s41567-025-03166-3","article_type":"original","OA_type":"hybrid","_id":"21295","title":"Discontinuous transition to shear flow turbulence","month":"02","article_processing_charge":"Yes (via OA deal)","citation":{"ieee":"B. Yang, Y. Zhuang, G. Yalniz, M. Vasudevan, E. Marensi, and B. Hof, “Discontinuous transition to shear flow turbulence,” <i>Nature Physics</i>. Springer Nature, 2026.","short":"B. Yang, Y. Zhuang, G. Yalniz, M. Vasudevan, E. Marensi, B. Hof, Nature Physics (2026).","mla":"Yang, Bowen, et al. “Discontinuous Transition to Shear Flow Turbulence.” <i>Nature Physics</i>, Springer Nature, 2026, doi:<a href=\"https://doi.org/10.1038/s41567-025-03166-3\">10.1038/s41567-025-03166-3</a>.","chicago":"Yang, Bowen, Yi Zhuang, Gökhan Yalniz, Mukund Vasudevan, Elena Marensi, and Björn Hof. “Discontinuous Transition to Shear Flow Turbulence.” <i>Nature Physics</i>. Springer Nature, 2026. <a href=\"https://doi.org/10.1038/s41567-025-03166-3\">https://doi.org/10.1038/s41567-025-03166-3</a>.","ista":"Yang B, Zhuang Y, Yalniz G, Vasudevan M, Marensi E, Hof B. 2026. Discontinuous transition to shear flow turbulence. Nature Physics.","ama":"Yang B, Zhuang Y, Yalniz G, Vasudevan M, Marensi E, Hof B. Discontinuous transition to shear flow turbulence. <i>Nature Physics</i>. 2026. doi:<a href=\"https://doi.org/10.1038/s41567-025-03166-3\">10.1038/s41567-025-03166-3</a>","apa":"Yang, B., Zhuang, Y., Yalniz, G., Vasudevan, M., Marensi, E., &#38; Hof, B. (2026). Discontinuous transition to shear flow turbulence. <i>Nature Physics</i>. Springer Nature. <a href=\"https://doi.org/10.1038/s41567-025-03166-3\">https://doi.org/10.1038/s41567-025-03166-3</a>"},"PlanS_conform":"1","has_accepted_license":"1","date_published":"2026-02-17T00:00:00Z","project":[{"name":"Revisiting the Turbulence Problem Using Statistical Mechanics","grant_number":"662960","_id":"238598C6-32DE-11EA-91FC-C7463DDC885E"}],"year":"2026","oa_version":"Published Version","date_updated":"2026-02-23T11:36:46Z","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","status":"public","tmp":{"short":"CC BY (4.0)","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)"},"day":"17","publisher":"Springer Nature","type":"journal_article"},{"has_accepted_license":"1","date_published":"2025-09-26T00:00:00Z","project":[{"name":"Revisiting the Turbulence Problem Using Statistical Mechanics","grant_number":"662960","_id":"238598C6-32DE-11EA-91FC-C7463DDC885E"}],"date_updated":"2025-12-01T12:40:27Z","year":"2025","oa_version":"Published Version","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","status":"public","tmp":{"short":"CC BY (4.0)","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)"},"type":"journal_article","day":"26","publisher":"Springer Nature","ddc":["532"],"arxiv":1,"article_type":"original","OA_type":"gold","doi":"10.1038/s41467-025-63044-7","OA_place":"publisher","_id":"20402","month":"09","title":"Aging and memory of transitional turbulence","article_processing_charge":"Yes","PlanS_conform":"1","citation":{"ista":"Vasudevan M, Paranjape CS, Sitte MP, Yalniz G, Hof B. 2025. Aging and memory of transitional turbulence. Nature Communications. 16, 8447.","chicago":"Vasudevan, Mukund, Chaitanya S Paranjape, Michael Philip Sitte, Gökhan Yalniz, and Björn Hof. “Aging and Memory of Transitional Turbulence.” <i>Nature Communications</i>. Springer Nature, 2025. <a href=\"https://doi.org/10.1038/s41467-025-63044-7\">https://doi.org/10.1038/s41467-025-63044-7</a>.","apa":"Vasudevan, M., Paranjape, C. S., Sitte, M. P., Yalniz, G., &#38; Hof, B. (2025). Aging and memory of transitional turbulence. <i>Nature Communications</i>. Springer Nature. <a href=\"https://doi.org/10.1038/s41467-025-63044-7\">https://doi.org/10.1038/s41467-025-63044-7</a>","ama":"Vasudevan M, Paranjape CS, Sitte MP, Yalniz G, Hof B. Aging and memory of transitional turbulence. <i>Nature Communications</i>. 2025;16. doi:<a href=\"https://doi.org/10.1038/s41467-025-63044-7\">10.1038/s41467-025-63044-7</a>","ieee":"M. Vasudevan, C. S. Paranjape, M. P. Sitte, G. Yalniz, and B. Hof, “Aging and memory of transitional turbulence,” <i>Nature Communications</i>, vol. 16. Springer Nature, 2025.","short":"M. Vasudevan, C.S. Paranjape, M.P. Sitte, G. Yalniz, B. Hof, Nature Communications 16 (2025).","mla":"Vasudevan, Mukund, et al. “Aging and Memory of Transitional Turbulence.” <i>Nature Communications</i>, vol. 16, 8447, Springer Nature, 2025, doi:<a href=\"https://doi.org/10.1038/s41467-025-63044-7\">10.1038/s41467-025-63044-7</a>."},"file_date_updated":"2025-09-27T13:32:03Z","scopus_import":"1","author":[{"full_name":"Vasudevan, Mukund","last_name":"Vasudevan","id":"3C5A959A-F248-11E8-B48F-1D18A9856A87","first_name":"Mukund"},{"id":"3D85B7C4-F248-11E8-B48F-1D18A9856A87","first_name":"Chaitanya S","full_name":"Paranjape, Chaitanya S","last_name":"Paranjape"},{"full_name":"Sitte, Michael Philip","last_name":"Sitte","id":"0ba0f1f2-9cfe-11f0-bee6-f95318d225b0","first_name":"Michael Philip"},{"first_name":"Gökhan","id":"66E74FA2-D8BF-11E9-8249-8DE2E5697425","full_name":"Yalniz, Gökhan","last_name":"Yalniz","orcid":"0000-0002-8490-9312"},{"orcid":"0000-0003-2057-2754","id":"3A374330-F248-11E8-B48F-1D18A9856A87","first_name":"Björn","last_name":"Hof","full_name":"Hof, Björn"}],"publication":"Nature Communications","intvolume":"        16","isi":1,"DOAJ_listed":"1","acknowledgement":"This work was supported by a grant from the Simons Foundation (662960, BH). We thank Yohann Duguet for helpful discussions, Baofang Song for the initial adaptation of openpipeflow57 to the channel geometry, and Ashley P. Willis for openpipeflow57.","file":[{"file_size":2226082,"file_id":"20403","date_created":"2025-09-27T13:32:03Z","file_name":"s41467-025-63044-7.pdf","creator":"gyalniz","date_updated":"2025-09-27T13:32:03Z","content_type":"application/pdf","checksum":"945926ead9cde464435d456427e2869e","relation":"main_file","access_level":"open_access"}],"publication_identifier":{"eissn":["2041-1723"]},"oa":1,"publication_status":"published","date_created":"2025-09-27T13:27:31Z","department":[{"_id":"BjHo"}],"external_id":{"isi":["001582555200041"],"arxiv":["2112.06537"]},"corr_author":"1","language":[{"iso":"eng"}],"volume":16,"quality_controlled":"1","article_number":"8447","abstract":[{"text":"The recent classification of the onset of turbulence as a directed percolation (DP) phase transition has been applied to all major shear flows including pipe, channel, Couette and boundary layer flows. A cornerstone of the DP analogy is the memoryless (Poisson) property of turbulent sites. We here show that, for the classic case of channel flow, neither the decay nor the proliferation of turbulent stripes is memoryless. As demonstrated by a standard analysis of the respective survival curves, isolated channel stripes, in the immediate vicinity of the critical point, age. Consequently, the one to one mapping between turbulent stripes and active DP-sites is not fulfilled in this low Reynolds number regime. In addition, the interpretation of turbulence as a chaotic saddle with supertransient properties, the basis of recent theoretical progress, does not apply to individual localized stripes. The discrepancy between channel flow and the transition models established for pipe and Couette flow, illustrates that seemingly minor geometrical differences between flows can give rise to instabilities and growth mechanisms that fundamentally alter the nature of the transition to turbulence.","lang":"eng"}]},{"OA_place":"publisher","doi":"10.15479/AT-ISTA-19684","alternative_title":["ISTA Thesis"],"ddc":["514","519","532","004"],"citation":{"ieee":"G. Yalniz, “Transition to turbulence : Data-, solution-, and pattern-driven approaches,” Institute of Science and Technology Austria, 2025.","short":"G. Yalniz, Transition to Turbulence : Data-, Solution-, and Pattern-Driven Approaches, Institute of Science and Technology Austria, 2025.","mla":"Yalniz, Gökhan. <i>Transition to Turbulence : Data-, Solution-, and Pattern-Driven Approaches</i>. Institute of Science and Technology Austria, 2025, doi:<a href=\"https://doi.org/10.15479/AT-ISTA-19684\">10.15479/AT-ISTA-19684</a>.","ista":"Yalniz G. 2025. Transition to turbulence : Data-, solution-, and pattern-driven approaches. Institute of Science and Technology Austria.","chicago":"Yalniz, Gökhan. “Transition to Turbulence : Data-, Solution-, and Pattern-Driven Approaches.” Institute of Science and Technology Austria, 2025. <a href=\"https://doi.org/10.15479/AT-ISTA-19684\">https://doi.org/10.15479/AT-ISTA-19684</a>.","apa":"Yalniz, G. (2025). <i>Transition to turbulence : Data-, solution-, and pattern-driven approaches</i>. Institute of Science and Technology Austria. <a href=\"https://doi.org/10.15479/AT-ISTA-19684\">https://doi.org/10.15479/AT-ISTA-19684</a>","ama":"Yalniz G. Transition to turbulence : Data-, solution-, and pattern-driven approaches. 2025. doi:<a href=\"https://doi.org/10.15479/AT-ISTA-19684\">10.15479/AT-ISTA-19684</a>"},"related_material":{"record":[{"status":"public","relation":"part_of_dissertation","id":"7563"},{"status":"public","relation":"part_of_dissertation","id":"9558"},{"id":"12105","status":"public","relation":"part_of_dissertation"},{"status":"public","relation":"part_of_dissertation","id":"13274"},{"relation":"part_of_dissertation","status":"public","id":"14466"}]},"article_processing_charge":"No","title":"Transition to turbulence : Data-, solution-, and pattern-driven approaches","month":"05","_id":"19684","page":"155","user_id":"ba8df636-2132-11f1-aed0-ed93e2281fdd","oa_version":"Published Version","year":"2025","date_updated":"2026-04-07T11:47:06Z","has_accepted_license":"1","project":[{"name":"Revisiting the Turbulence Problem Using Statistical Mechanics","_id":"238598C6-32DE-11EA-91FC-C7463DDC885E","grant_number":"662960"}],"date_published":"2025-05-13T00:00:00Z","publisher":"Institute of Science and Technology Austria","type":"dissertation","day":"13","status":"public","language":[{"iso":"eng"}],"corr_author":"1","department":[{"_id":"GradSch"},{"_id":"BjHo"}],"date_created":"2025-05-12T15:12:28Z","publication_status":"published","degree_awarded":"PhD","acknowledged_ssus":[{"_id":"ScienComp"}],"abstract":[{"lang":"eng","text":"The overarching goal of this thesis is to break down the complexity of turbulent flows in terms of enumerable, coherent structures and patterns. In a five-paper series, we adopt a variety of perspectives and techniques to relate the properties of systems of increasing complexity to their underlying coherent structures. \r\n\r\nInitially, we take a dynamical systems point of view, seeing turbulent flow as a chaotic trajectory bouncing between exact unstable solutions of the underlying equations of motion. Using persistent homology, the main tool of topological data analysis capturing the persistence across scales of topological features in a point cloud, we introduce a method that quantifies visits of turbulent trajectories to unstable time-periodic solutions, also called periodic orbits. We demonstrate this method first in the Rössler and Kuramoto–Sivashinsky systems. Using this method in 3D Kolmogorov flow, we extract a Markov chain from turbulent data, where each node corresponds to the neighbourhood of a periodic orbit. The invariant distribution of this Markov chain reproduces expectation values on turbulent data when it is used to weight averages on the respective periodic orbits.\r\n\r\nIn more realistic, wall-bounded settings, such as plane-Couette flow (pcf) driven by the relative motion of the walls, or plane-Poiseuille flow (ppf) driven by a pressure gradient, finding exact solutions is difficult. We use dynamic mode decomposition (DMD), a dimensionality reduction method for sequential data, to identify and approximate low-dimensional dynamics without knowing any exact solutions. Most spatially-extended systems are equivariant under translations, and in such cases spatial drifts dominate DMD, hindering its use in the search for and modelling of low-dimensional dynamics. We augment DMD with a symmetry reduction method trained on turbulent data to stop it from seeing translations as a feature, improving its ability to extract dynamical information in translation-equivariant systems. We find segments of turbulent trajectories that linearize well with their symmetry-reduced DMD spectra, akin to dynamics near exact solutions. Searching for harmonics in the spectra gives leads for periodic orbits with spatial drifts, one of which converges to a new solution.\r\n\r\nIn larger domains, turbulence can localize and coexist with surrounding laminar flow. Our preceding approaches are global, taking all of a domain into account at once, and cannot readily treat each localized patch individually. Working first in a minimal oblique domain that can host a single 1D-localized turbulent patch, we find that turbulence in ppf is connected to a stable periodic orbit at a flow velocity much lower than when turbulence is first onset. We show that, well in advance of sustained turbulence, chaos sets in explosively, and for long time horizons, time series are consistent with that of a random process.\r\n\r\nFinally, in much larger domains, we study and compare 2D-localized turbulence that appears as large-scale inclined structures, called stripes, in ppf and pcf. While appearing similar, we find that stripes in these two settings differ significantly in terms of how they sustain themselves, and in higher velocities, how they proliferate."}],"supervisor":[{"first_name":"Björn","id":"3A374330-F248-11E8-B48F-1D18A9856A87","last_name":"Hof","full_name":"Hof, Björn","orcid":"0000-0003-2057-2754"}],"file_date_updated":"2025-05-12T15:43:28Z","author":[{"orcid":"0000-0002-8490-9312","id":"66E74FA2-D8BF-11E9-8249-8DE2E5697425","first_name":"Gökhan","full_name":"Yalniz, Gökhan","last_name":"Yalniz"}],"oa":1,"publication_identifier":{"issn":["2663-337X"]},"file":[{"date_updated":"2025-05-12T15:13:28Z","content_type":"application/pdf","checksum":"0e452642b79f13633f1595bde71a67e3","file_size":20058169,"creator":"gyalniz","file_name":"Gökhan Yalnız - PhD thesis.pdf","file_id":"19685","date_created":"2025-05-12T15:13:28Z","access_level":"open_access","relation":"main_file","success":1},{"description":"3D visualizations of the turbulent flow (left) and the periodic orbits (middle) that are being shadowed along with the local state space projections (right) onto the principal components of the respective periodic orbit. Shown here are the isosurfaces of velocity (red/blue: ±95% of the instantaneous maximum) and vorticity (purple/green: ±65% of the instantaneous maximum) in the x-direction. Markers along the projections are in sync with the 3D visualizations. The movie corresponds to the initial time interval (up to t = 100) of figure 2.2 (a,b); periodic orbits and the state space projections are shown only through the shadowing events indicated in figure 2.2 (b).","file_size":37763743,"file_id":"19686","date_created":"2025-05-12T15:15:59Z","creator":"gyalniz","file_name":"Movie 2A.1.mp4","date_updated":"2025-05-12T15:43:28Z","checksum":"921099d76adab2df784ce12ce41cfb22","content_type":"video/mp4","title":"Chapter 2 - Movie 2A.1","relation":"supplementary_material","access_level":"open_access"},{"date_updated":"2025-05-12T15:43:28Z","checksum":"0ae5ac7d9896003c0c4207dd746808dc","content_type":"video/mp4","description":"Turbulent flow (left) in HKW domain and its symmetry reduction (right). Shown here are the isosurfaces of streamwise velocity (red/blue: u = 0.5 max/min u) and streamwise vorticity (green/purple: ω_x = 0.5 max/min ω_x).","file_size":3902655,"file_id":"19687","date_created":"2025-05-12T15:16:09Z","creator":"gyalniz","file_name":"Movie 3A.1.mp4","title":"Chapter 3 - Movie 3A.1","relation":"supplementary_material","access_level":"open_access"},{"access_level":"open_access","relation":"supplementary_material","title":"Chapter 3 - Movie 3A.2","creator":"gyalniz","file_name":"Movie 3A.2.mp4","date_created":"2025-05-12T15:16:21Z","file_id":"19688","file_size":7043169,"description":"Turbulent flow (left) in P2K domain and its symmetry reduction (right). Shown here are the isosurfaces of streamwise velocity (red/blue: u = 0.5 max/min u) and streamwise vorticity (green/purple: ω_x = 0.5 max/min ω_x).","content_type":"video/mp4","checksum":"ef8d270e066c1a9c3cb5ae46acf945e6","date_updated":"2025-05-12T15:43:28Z"},{"title":"Chapter 3 - Movie 3A.3","access_level":"open_access","relation":"supplementary_material","file_size":7748659,"description":"Relative periodic orbit RPO_79.4 (left) of the plane-Couette flow (HKW domain) and its symmetry reduction (right). Shown here are the isosurfaces of streamwise velocity (red/blue: u = 0.5 max/min u) and streamwise vorticity (green/purple: ω_x = 0.5 max/min ω_x).","file_name":"Movie 3A.3.mp4","creator":"gyalniz","file_id":"19689","date_created":"2025-05-12T15:16:36Z","date_updated":"2025-05-12T15:43:28Z","content_type":"video/mp4","checksum":"7ed871f428100d6827ac9b0e8ca8e985"},{"date_updated":"2025-05-12T15:43:28Z","content_type":"video/mp4","checksum":"dd5a252e1da00c8f303588e22e2baeef","file_size":5873052,"description":"Symmetry-reduced flow (left), its SRDMD approximation (middle), and state space projection (right) showing the spiral-out episode in P2K domain (figure 3.6 (b) and figure 3.8 (b)). Shown here are the isosurfaces of streamwise velocity (red/blue: u = 0.5 max/min u) and streamwise vorticity (green/purple: ω_x = 0.5 max/min ω_x).","file_name":"Movie 3A.4.mp4","creator":"gyalniz","file_id":"19690","date_created":"2025-05-12T15:16:50Z","title":"Chapter 3 - Movie 3A.4","access_level":"open_access","relation":"supplementary_material"},{"description":"Movie demonstrating the quasi-steady Reynolds number descent from turbulence to a periodic orbit.","file_size":9209327,"date_created":"2025-05-12T15:17:11Z","file_id":"19691","file_name":"Movie 4A.1.mp4","creator":"gyalniz","date_updated":"2025-05-12T15:43:28Z","checksum":"5ac58b86810698db28cbfc28f351ff70","content_type":"video/mp4","title":"Chapter 4 - Movie 4A.1","relation":"supplementary_material","access_level":"open_access"},{"date_updated":"2025-05-12T15:43:28Z","content_type":"video/mp4","checksum":"ac877f1e1ef39439911bf37cb1793b8e","description":"Streamwise velocity fluctuations (from laminar) of plane-Couette flow (Re^C =335) at the y = 0 wall-normal plane in coordinates stationary with respect to the bulk velocity. Here, x is the streamwise direction (the wall at y = 1 moves to the right) and z is the spanwise direction. Time is in advectime time units. Shown is the full (L_x = L_z = 400) domain.","file_size":5893993,"file_id":"19692","date_created":"2025-05-12T15:17:43Z","file_name":"Movie 5A.1.mp4","creator":"gyalniz","title":"Chapter 5 - Movie 5A.1","relation":"supplementary_material","access_level":"open_access"},{"relation":"supplementary_material","access_level":"open_access","title":"Chapter 5 - Movie 5A.2","date_created":"2025-05-12T15:17:49Z","file_id":"19693","creator":"gyalniz","file_name":"Movie 5A.2.mp4","description":"Streamwise velocity fluctuations (from laminar) of plane-Poiseuille flow (Re^P =660) at the y = 0.5 wall-normal plane in coordinates stationary with respect to the bulk velocity. Here, x is the streamwise direction (the mean negative pressure gradient is to the right) and z is the spanwise direction. Time is in advectime time units. Shown is the full (L_x = L_z = 400) domain.","file_size":3990352,"checksum":"fd17eabb70129ceaa414e40924d1d2fe","content_type":"video/mp4","date_updated":"2025-05-12T15:43:28Z"},{"file_size":5171009,"description":"Streamwise velocity fluctuations (from laminar) of plane-Poiseuille flow (Re^P=660) at the y = 0.5 wall-normal plane in coordinates stationary with respect to the average velocity of the downstream tip of the stripe. Here, x is the streamwise direction (the mean negative pressure gradient is to the right) and z is the spanwise direction. Time is in advectime time units. Shown is a zoom-in of the full (L_x = L_z) domain.","file_name":"Movie 5A.3.mp4","creator":"gyalniz","date_created":"2025-05-12T15:17:58Z","file_id":"19694","date_updated":"2025-05-12T15:43:28Z","content_type":"video/mp4","checksum":"32f904497ab0bbee38f0788d96b91454","title":"Chapter 5 - Movie 5A.3","access_level":"open_access","relation":"supplementary_material"},{"date_updated":"2025-05-12T15:43:28Z","content_type":"application/x-zip-compressed","checksum":"f313261b9bb12dfb943fead8318954c6","file_size":18991996,"creator":"gyalniz","file_name":"Gökhan Yalnız - PhD thesis.zip","date_created":"2025-05-12T15:27:10Z","file_id":"19695","access_level":"closed","relation":"source_file"}],"acknowledgement":"The work in this thesis was supported by a grant from the Simons Foundation (662960, BH).\r\n"},{"acknowledgement":"We gratefully acknowledge the assistance of J. M. Lopez with DNSs at an early stage of this work. This work was partially supported by two grants from the Simons Foundation (grant nos. 662985 (N.G.) and 662960 (B.H.)) and by Ministry of Science and Technology, Taiwan (grant nos. MOST 109-2112-M-001-017-MY3 and MOST 111-2112-M-001-027-MY3 (H.-Y.S.)). Part of this work was performed using computing resources of CRIANN (Normandy, France).","publication_identifier":{"eissn":["1745-2481"],"issn":["1745-2473"]},"publication":"Nature Physics","scopus_import":"1","author":[{"first_name":"Grégoire M","id":"4787FE80-F248-11E8-B48F-1D18A9856A87","full_name":"Lemoult, Grégoire M","last_name":"Lemoult"},{"last_name":"Vasudevan","full_name":"Vasudevan, Mukund","first_name":"Mukund","id":"3C5A959A-F248-11E8-B48F-1D18A9856A87"},{"last_name":"Shih","full_name":"Shih, Hong Yan","first_name":"Hong Yan"},{"full_name":"Linga, Gaute","last_name":"Linga","first_name":"Gaute"},{"last_name":"Mathiesen","full_name":"Mathiesen, Joachim","first_name":"Joachim"},{"full_name":"Goldenfeld, Nigel","last_name":"Goldenfeld","first_name":"Nigel"},{"full_name":"Hof, Björn","last_name":"Hof","first_name":"Björn","id":"3A374330-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0003-2057-2754"}],"intvolume":"        20","isi":1,"abstract":[{"text":"The onset of turbulence in pipe flow has defied detailed understanding ever since the first observations of the spatially heterogeneous nature of the transition. Recent theoretical studies and experiments in simpler, shear-driven flows suggest that the onset of turbulence is a directed-percolation non-equilibrium phase transition, but whether these findings are generic and also apply to open or pressure-driven flows is unknown. In pipe flow, the extremely long time scales near the transition make direct observations of critical behaviour virtually impossible. Here we find a technical solution to that limitation and show that the universality class of the transition is directed percolation, from which a jammed phase of puffs emerges above the critical point. Our method is to experimentally characterize all pairwise interactions between localized patches of turbulence puffs and use these interactions as input for renormalization group and computer simulations of minimal models that extrapolate to long length and time scales. The strong interactions in the jamming regime enable us to explicitly measure the turbulent fraction and confirm model predictions. Our work shows that directed-percolation scaling applies beyond simple closed shear flows and underscores how statistical mechanics can lead to profound, quantitative and predictive insights on turbulent flows and their phases.","lang":"eng"}],"volume":20,"quality_controlled":"1","external_id":{"isi":["001232300600001"]},"department":[{"_id":"BjHo"}],"date_created":"2024-06-09T22:01:03Z","language":[{"iso":"eng"}],"corr_author":"1","publication_status":"published","day":"01","type":"journal_article","publisher":"Springer Nature","status":"public","user_id":"317138e5-6ab7-11ef-aa6d-ffef3953e345","page":"1339-1345","date_published":"2024-08-01T00:00:00Z","project":[{"_id":"238598C6-32DE-11EA-91FC-C7463DDC885E","grant_number":"662960","name":"Revisiting the Turbulence Problem Using Statistical Mechanics"}],"oa_version":"None","year":"2024","date_updated":"2025-09-08T07:50:20Z","article_processing_charge":"No","citation":{"ieee":"G. M. Lemoult <i>et al.</i>, “Directed percolation and puff jamming near the transition to pipe turbulence,” <i>Nature Physics</i>, vol. 20. Springer Nature, pp. 1339–1345, 2024.","mla":"Lemoult, Grégoire M., et al. “Directed Percolation and Puff Jamming near the Transition to Pipe Turbulence.” <i>Nature Physics</i>, vol. 20, Springer Nature, 2024, pp. 1339–45, doi:<a href=\"https://doi.org/10.1038/s41567-024-02513-0\">10.1038/s41567-024-02513-0</a>.","short":"G.M. Lemoult, M. Vasudevan, H.Y. Shih, G. Linga, J. Mathiesen, N. Goldenfeld, B. Hof, Nature Physics 20 (2024) 1339–1345.","chicago":"Lemoult, Grégoire M, Mukund Vasudevan, Hong Yan Shih, Gaute Linga, Joachim Mathiesen, Nigel Goldenfeld, and Björn Hof. “Directed Percolation and Puff Jamming near the Transition to Pipe Turbulence.” <i>Nature Physics</i>. Springer Nature, 2024. <a href=\"https://doi.org/10.1038/s41567-024-02513-0\">https://doi.org/10.1038/s41567-024-02513-0</a>.","ista":"Lemoult GM, Vasudevan M, Shih HY, Linga G, Mathiesen J, Goldenfeld N, Hof B. 2024. Directed percolation and puff jamming near the transition to pipe turbulence. Nature Physics. 20, 1339–1345.","ama":"Lemoult GM, Vasudevan M, Shih HY, et al. Directed percolation and puff jamming near the transition to pipe turbulence. <i>Nature Physics</i>. 2024;20:1339-1345. doi:<a href=\"https://doi.org/10.1038/s41567-024-02513-0\">10.1038/s41567-024-02513-0</a>","apa":"Lemoult, G. M., Vasudevan, M., Shih, H. Y., Linga, G., Mathiesen, J., Goldenfeld, N., &#38; Hof, B. (2024). Directed percolation and puff jamming near the transition to pipe turbulence. <i>Nature Physics</i>. Springer Nature. <a href=\"https://doi.org/10.1038/s41567-024-02513-0\">https://doi.org/10.1038/s41567-024-02513-0</a>"},"_id":"17128","title":"Directed percolation and puff jamming near the transition to pipe turbulence","month":"08","doi":"10.1038/s41567-024-02513-0","article_type":"original"},{"quality_controlled":"1","volume":621,"acknowledged_ssus":[{"_id":"M-Shop"},{"_id":"ScienComp"}],"abstract":[{"text":"Flows through pipes and channels are, in practice, almost always turbulent, and the multiscale eddying motion is responsible for a major part of the encountered friction losses and pumping costs1. Conversely, for pulsatile flows, in particular for aortic blood flow, turbulence levels remain low despite relatively large peak velocities. For aortic blood flow, high turbulence levels are intolerable as they would damage the shear-sensitive endothelial cell layer2,3,4,5. Here we show that turbulence in ordinary pipe flow is diminished if the flow is driven in a pulsatile mode that incorporates all the key features of the cardiac waveform. At Reynolds numbers comparable to those of aortic blood flow, turbulence is largely inhibited, whereas at much higher speeds, the turbulent drag is reduced by more than 25%. This specific operation mode is more efficient when compared with steady driving, which is the present situation for virtually all fluid transport processes ranging from heating circuits to water, gas and oil pipelines.","lang":"eng"}],"publication_status":"published","corr_author":"1","language":[{"iso":"eng"}],"department":[{"_id":"BjHo"}],"external_id":{"isi":["001168947700009"],"pmid":["37673988"]},"date_created":"2023-09-17T22:01:09Z","oa":1,"publication_identifier":{"issn":["0028-0836"],"eissn":["1476-4687"]},"acknowledgement":"We acknowledge the assistance of the Miba machine shop and the team of the ISTA-HPC cluster. We thank M. Quadrio for the discussions. The work was supported by the Simons Foundation (grant no. 662960) and by the Austrian Science Fund (grant no. I4188-N30), within Deutsche Forschungsgemeinschaft research unit FOR 2688.","file":[{"access_level":"open_access","relation":"main_file","success":1,"date_updated":"2024-06-04T09:24:34Z","checksum":"9c9f172ba0a9a301d76fff4229812464","content_type":"application/pdf","file_size":3247252,"creator":"dernst","file_name":"2023_submittedversion.pdf","date_created":"2024-06-04T09:24:34Z","file_id":"17118"}],"pmid":1,"intvolume":"       621","isi":1,"author":[{"orcid":"0000-0001-5227-4271","id":"40315C30-F248-11E8-B48F-1D18A9856A87","first_name":"Davide","full_name":"Scarselli, Davide","last_name":"Scarselli"},{"first_name":"Jose M","id":"40770848-F248-11E8-B48F-1D18A9856A87","last_name":"Lopez Alonso","full_name":"Lopez Alonso, Jose M","orcid":"0000-0002-0384-2022"},{"orcid":"0000-0002-3072-5999","id":"2A2006B2-F248-11E8-B48F-1D18A9856A87","first_name":"Atul","last_name":"Varshney","full_name":"Varshney, Atul"},{"first_name":"Björn","id":"3A374330-F248-11E8-B48F-1D18A9856A87","last_name":"Hof","full_name":"Hof, Björn","orcid":"0000-0003-2057-2754"}],"scopus_import":"1","file_date_updated":"2024-06-04T09:24:34Z","publication":"Nature","title":"Turbulence suppression by cardiac-cycle-inspired driving of pipe flow","month":"09","_id":"14341","citation":{"ama":"Scarselli D, Lopez Alonso JM, Varshney A, Hof B. Turbulence suppression by cardiac-cycle-inspired driving of pipe flow. <i>Nature</i>. 2023;621(7977):71-74. doi:<a href=\"https://doi.org/10.1038/s41586-023-06399-5\">10.1038/s41586-023-06399-5</a>","apa":"Scarselli, D., Lopez Alonso, J. M., Varshney, A., &#38; Hof, B. (2023). Turbulence suppression by cardiac-cycle-inspired driving of pipe flow. <i>Nature</i>. Springer Nature. <a href=\"https://doi.org/10.1038/s41586-023-06399-5\">https://doi.org/10.1038/s41586-023-06399-5</a>","chicago":"Scarselli, Davide, Jose M Lopez Alonso, Atul Varshney, and Björn Hof. “Turbulence Suppression by Cardiac-Cycle-Inspired Driving of Pipe Flow.” <i>Nature</i>. Springer Nature, 2023. <a href=\"https://doi.org/10.1038/s41586-023-06399-5\">https://doi.org/10.1038/s41586-023-06399-5</a>.","ista":"Scarselli D, Lopez Alonso JM, Varshney A, Hof B. 2023. Turbulence suppression by cardiac-cycle-inspired driving of pipe flow. Nature. 621(7977), 71–74.","short":"D. Scarselli, J.M. Lopez Alonso, A. Varshney, B. Hof, Nature 621 (2023) 71–74.","mla":"Scarselli, Davide, et al. “Turbulence Suppression by Cardiac-Cycle-Inspired Driving of Pipe Flow.” <i>Nature</i>, vol. 621, no. 7977, Springer Nature, 2023, pp. 71–74, doi:<a href=\"https://doi.org/10.1038/s41586-023-06399-5\">10.1038/s41586-023-06399-5</a>.","ieee":"D. Scarselli, J. M. Lopez Alonso, A. Varshney, and B. Hof, “Turbulence suppression by cardiac-cycle-inspired driving of pipe flow,” <i>Nature</i>, vol. 621, no. 7977. Springer Nature, pp. 71–74, 2023."},"related_material":{"link":[{"relation":"press_release","url":"https://www.ista.ac.at/en/news/pumping-like-the-heart/","description":"News on ISTA website"}]},"article_processing_charge":"No","ddc":["530"],"doi":"10.1038/s41586-023-06399-5","article_type":"original","status":"public","day":"07","publisher":"Springer Nature","type":"journal_article","issue":"7977","year":"2023","oa_version":"Submitted Version","date_updated":"2025-09-09T12:59:04Z","has_accepted_license":"1","date_published":"2023-09-07T00:00:00Z","project":[{"_id":"238598C6-32DE-11EA-91FC-C7463DDC885E","grant_number":"662960","name":"Revisiting the Turbulence Problem Using Statistical Mechanics"},{"call_identifier":"FWF","name":"Instabilities in pulsating pipe flow in complex fluids","grant_number":"I04188","_id":"238B8092-32DE-11EA-91FC-C7463DDC885E"}],"page":"71-74","user_id":"317138e5-6ab7-11ef-aa6d-ffef3953e345"},{"tmp":{"short":"CC BY (4.0)","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)"},"status":"public","type":"journal_article","publisher":"Annual Reviews","day":"19","date_updated":"2024-10-22T11:08:43Z","year":"2023","oa_version":"Published Version","has_accepted_license":"1","date_published":"2023-01-19T00:00:00Z","project":[{"name":"Revisiting the Turbulence Problem Using Statistical Mechanics","_id":"238598C6-32DE-11EA-91FC-C7463DDC885E","grant_number":"662960"}],"page":"575-602","user_id":"4359f0d1-fa6c-11eb-b949-802e58b17ae8","month":"01","title":"Transition to turbulence in pipe flow","_id":"12682","citation":{"ieee":"M. Avila, D. Barkley, and B. Hof, “Transition to turbulence in pipe flow,” <i>Annual Review of Fluid Mechanics</i>, vol. 55. Annual Reviews, pp. 575–602, 2023.","mla":"Avila, Marc, et al. “Transition to Turbulence in Pipe Flow.” <i>Annual Review of Fluid Mechanics</i>, vol. 55, Annual Reviews, 2023, pp. 575–602, doi:<a href=\"https://doi.org/10.1146/annurev-fluid-120720-025957\">10.1146/annurev-fluid-120720-025957</a>.","short":"M. Avila, D. Barkley, B. Hof, Annual Review of Fluid Mechanics 55 (2023) 575–602.","chicago":"Avila, Marc, Dwight Barkley, and Björn Hof. “Transition to Turbulence in Pipe Flow.” <i>Annual Review of Fluid Mechanics</i>. Annual Reviews, 2023. <a href=\"https://doi.org/10.1146/annurev-fluid-120720-025957\">https://doi.org/10.1146/annurev-fluid-120720-025957</a>.","ista":"Avila M, Barkley D, Hof B. 2023. Transition to turbulence in pipe flow. Annual Review of Fluid Mechanics. 55, 575–602.","ama":"Avila M, Barkley D, Hof B. Transition to turbulence in pipe flow. <i>Annual Review of Fluid Mechanics</i>. 2023;55:575-602. doi:<a href=\"https://doi.org/10.1146/annurev-fluid-120720-025957\">10.1146/annurev-fluid-120720-025957</a>","apa":"Avila, M., Barkley, D., &#38; Hof, B. (2023). Transition to turbulence in pipe flow. <i>Annual Review of Fluid Mechanics</i>. Annual Reviews. <a href=\"https://doi.org/10.1146/annurev-fluid-120720-025957\">https://doi.org/10.1146/annurev-fluid-120720-025957</a>"},"article_processing_charge":"No","ddc":["530"],"article_type":"original","doi":"10.1146/annurev-fluid-120720-025957","publication_identifier":{"issn":["0066-4189"]},"oa":1,"file":[{"checksum":"f99ef30f76cabc9e5e1946b380c16db4","content_type":"application/pdf","date_updated":"2023-02-27T09:35:52Z","file_id":"12691","date_created":"2023-02-27T09:35:52Z","creator":"dernst","file_name":"2023_AnnReviewFluidMech_Avila.pdf","file_size":4769537,"relation":"main_file","access_level":"open_access","success":1}],"acknowledgement":"The authors are very grateful to Laurette Tuckerman for her helpful comments. This work was supported by grants from the Simons Foundation (grant numbers 662985, D.B., and 662960, B.H.) and the Priority Programme “SPP 1881: Turbulent Superstructures” of the Deutsche Forschungsgemeinschaft (grant number AV120/3-2 to M.A.).","intvolume":"        55","isi":1,"publication":"Annual Review of Fluid Mechanics","author":[{"last_name":"Avila","full_name":"Avila, Marc","first_name":"Marc"},{"last_name":"Barkley","full_name":"Barkley, Dwight","first_name":"Dwight"},{"orcid":"0000-0003-2057-2754","first_name":"Björn","id":"3A374330-F248-11E8-B48F-1D18A9856A87","full_name":"Hof, Björn","last_name":"Hof"}],"file_date_updated":"2023-02-27T09:35:52Z","scopus_import":"1","quality_controlled":"1","volume":55,"abstract":[{"text":"Since the seminal studies by Osborne Reynolds in the nineteenth century, pipe flow has served as a primary prototype for investigating the transition to turbulence in wall-bounded flows. Despite the apparent simplicity of this flow, various facets of this problem have occupied researchers for more than a century. Here we review insights from three distinct perspectives: (a) stability and susceptibility of laminar flow, (b) phase transition and spatiotemporal dynamics, and (c) dynamical systems analysis of the Navier—Stokes equations. We show how these perspectives have led to a profound understanding of the onset of turbulence in pipe flow. Outstanding open points, applications to flows of complex fluids, and similarities with other wall-bounded flows are discussed.","lang":"eng"}],"publication_status":"published","language":[{"iso":"eng"}],"date_created":"2023-02-26T23:01:01Z","department":[{"_id":"BjHo"}],"external_id":{"isi":["000915418100023"]}},{"author":[{"first_name":"Elena","id":"0BE7553A-1004-11EA-B805-18983DDC885E","full_name":"Marensi, Elena","last_name":"Marensi","orcid":"0000-0001-7173-4923"},{"orcid":"0000-0002-8490-9312","id":"66E74FA2-D8BF-11E9-8249-8DE2E5697425","first_name":"Gökhan","last_name":"Yalniz","full_name":"Yalniz, Gökhan"},{"full_name":"Hof, Björn","last_name":"Hof","first_name":"Björn","id":"3A374330-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0003-2057-2754"}],"file_date_updated":"2024-02-15T09:05:21Z","keyword":["turbulence","transition to turbulence","patterns"],"publication":"Journal of Fluid Mechanics","scopus_import":"1","isi":1,"intvolume":"       974","acknowledgement":"E.M. acknowledges funding from the ISTplus fellowship programme. G.Y. and B.H. acknowledge a grant from the Simons Foundation (662960, BH).","file":[{"checksum":"17c64c1fb0d5f73252364bf98b0b9e1a","content_type":"application/pdf","date_updated":"2024-02-15T09:05:21Z","creator":"dernst","file_name":"2023_JourFluidMechanics_Marensi.pdf","file_id":"14996","date_created":"2024-02-15T09:05:21Z","file_size":2804641,"access_level":"open_access","relation":"main_file","success":1}],"publication_identifier":{"issn":["0022-1120"],"eissn":["1469-7645"]},"oa":1,"publication_status":"published","external_id":{"arxiv":["2212.12406"],"isi":["001088363700001"]},"department":[{"_id":"GradSch"},{"_id":"BjHo"}],"date_created":"2023-10-30T09:32:28Z","language":[{"iso":"eng"}],"corr_author":"1","volume":974,"quality_controlled":"1","abstract":[{"lang":"eng","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."}],"article_number":"A21","date_published":"2023-11-10T00:00:00Z","project":[{"name":"Revisiting the Turbulence Problem Using Statistical Mechanics","grant_number":"662960","_id":"238598C6-32DE-11EA-91FC-C7463DDC885E"}],"has_accepted_license":"1","year":"2023","oa_version":"Published Version","date_updated":"2026-04-07T11:47:05Z","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","status":"public","tmp":{"short":"CC BY (4.0)","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)"},"publisher":"Cambridge University Press","type":"journal_article","day":"10","arxiv":1,"ddc":["530"],"doi":"10.1017/jfm.2023.780","article_type":"original","_id":"14466","title":"Dynamics and proliferation of turbulent stripes in plane-Poiseuille and plane-Couette flows","month":"11","article_processing_charge":"Yes (via OA deal)","citation":{"short":"E. Marensi, G. Yalniz, B. Hof, Journal of Fluid Mechanics 974 (2023).","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>.","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>","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.","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>."},"related_material":{"record":[{"relation":"dissertation_contains","status":"public","id":"19684"}]}},{"corr_author":"1","language":[{"iso":"eng"}],"date_created":"2023-01-08T23:00:53Z","department":[{"_id":"BjHo"}],"external_id":{"isi":["000903336600001"],"arxiv":["2101.07516"]},"publication_status":"published","article_number":"A10","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."}],"quality_controlled":"1","volume":954,"intvolume":"       954","isi":1,"publication":"Journal of Fluid Mechanics","scopus_import":"1","file_date_updated":"2023-02-02T12:34:54Z","author":[{"id":"0BE7553A-1004-11EA-B805-18983DDC885E","first_name":"Elena","last_name":"Marensi","full_name":"Marensi, Elena","orcid":"0000-0001-7173-4923"},{"full_name":"Yalniz, Gökhan","last_name":"Yalniz","first_name":"Gökhan","id":"66E74FA2-D8BF-11E9-8249-8DE2E5697425","orcid":"0000-0002-8490-9312"},{"id":"3A374330-F248-11E8-B48F-1D18A9856A87","first_name":"Björn","last_name":"Hof","full_name":"Hof, Björn","orcid":"0000-0003-2057-2754"},{"orcid":"0000-0003-0423-5010","full_name":"Budanur, Nazmi B","last_name":"Budanur","id":"3EA1010E-F248-11E8-B48F-1D18A9856A87","first_name":"Nazmi B"}],"oa":1,"publication_identifier":{"issn":["0022-1120"],"eissn":["1469-7645"]},"file":[{"success":1,"access_level":"open_access","relation":"main_file","file_name":"2023_JourFluidMechanics_Marensi.pdf","creator":"dernst","date_created":"2023-02-02T12:34:54Z","file_id":"12489","file_size":1931647,"checksum":"9224f987caefe5dd85a70814d3cce65c","content_type":"application/pdf","date_updated":"2023-02-02T12:34:54Z"}],"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).","article_type":"original","doi":"10.1017/jfm.2022.1001","ddc":["530"],"arxiv":1,"related_material":{"record":[{"relation":"dissertation_contains","status":"public","id":"19684"}]},"citation":{"short":"E. Marensi, G. Yalniz, B. Hof, N.B. Budanur, Journal of Fluid Mechanics 954 (2023).","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>.","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.","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>","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>","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>.","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."},"article_processing_charge":"Yes (via OA deal)","month":"01","title":"Symmetry-reduced dynamic mode decomposition of near-wall turbulence","_id":"12105","user_id":"4359f0d1-fa6c-11eb-b949-802e58b17ae8","date_updated":"2026-04-07T11:47:05Z","oa_version":"Published Version","year":"2023","has_accepted_license":"1","project":[{"name":"Revisiting the Turbulence Problem Using Statistical Mechanics","_id":"238598C6-32DE-11EA-91FC-C7463DDC885E","grant_number":"662960"}],"date_published":"2023-01-10T00:00:00Z","day":"10","publisher":"Cambridge University Press","type":"journal_article","tmp":{"short":"CC BY (4.0)","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","image":"/images/cc_by.png","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)"},"status":"public"},{"article_processing_charge":"No","related_material":{"record":[{"id":"19684","relation":"dissertation_contains","status":"public"}]},"citation":{"mla":"Paranjape, Chaitanya S., et al. “Direct Path from Turbulence to Time-Periodic Solutions.” <i>Physical Review Letters</i>, vol. 131, no. 3, 034002, American Physical Society, 2023, doi:<a href=\"https://doi.org/10.1103/physrevlett.131.034002\">10.1103/physrevlett.131.034002</a>.","short":"C.S. Paranjape, G. Yalniz, Y. Duguet, N.B. Budanur, B. Hof, Physical Review Letters 131 (2023).","ieee":"C. S. Paranjape, G. Yalniz, Y. Duguet, N. B. Budanur, and B. Hof, “Direct path from turbulence to time-periodic solutions,” <i>Physical Review Letters</i>, vol. 131, no. 3. American Physical Society, 2023.","apa":"Paranjape, C. S., Yalniz, G., Duguet, Y., Budanur, N. B., &#38; Hof, B. (2023). Direct path from turbulence to time-periodic solutions. <i>Physical Review Letters</i>. American Physical Society. <a href=\"https://doi.org/10.1103/physrevlett.131.034002\">https://doi.org/10.1103/physrevlett.131.034002</a>","ama":"Paranjape CS, Yalniz G, Duguet Y, Budanur NB, Hof B. Direct path from turbulence to time-periodic solutions. <i>Physical Review Letters</i>. 2023;131(3). doi:<a href=\"https://doi.org/10.1103/physrevlett.131.034002\">10.1103/physrevlett.131.034002</a>","ista":"Paranjape CS, Yalniz G, Duguet Y, Budanur NB, Hof B. 2023. Direct path from turbulence to time-periodic solutions. Physical Review Letters. 131(3), 034002.","chicago":"Paranjape, Chaitanya S, Gökhan Yalniz, Yohann Duguet, Nazmi B Budanur, and Björn Hof. “Direct Path from Turbulence to Time-Periodic Solutions.” <i>Physical Review Letters</i>. American Physical Society, 2023. <a href=\"https://doi.org/10.1103/physrevlett.131.034002\">https://doi.org/10.1103/physrevlett.131.034002</a>."},"_id":"13274","month":"07","title":"Direct path from turbulence to time-periodic solutions","article_type":"original","doi":"10.1103/physrevlett.131.034002","arxiv":1,"issue":"3","day":"21","type":"journal_article","publisher":"American Physical Society","status":"public","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","date_published":"2023-07-21T00:00:00Z","project":[{"name":"Revisiting the Turbulence Problem Using Statistical Mechanics","_id":"238598C6-32DE-11EA-91FC-C7463DDC885E","grant_number":"662960"}],"date_updated":"2026-04-07T11:47:05Z","oa_version":"Preprint","year":"2023","article_number":"034002","abstract":[{"text":"Viscous flows through pipes and channels are steady and ordered until, with increasing velocity, the laminar motion catastrophically breaks down and gives way to turbulence. How this apparently discontinuous change from low- to high-dimensional motion can be rationalized within the framework of the Navier-Stokes equations is not well understood. Exploiting geometrical properties of transitional channel flow we trace turbulence to far lower Reynolds numbers (Re) than previously possible and identify the complete path that reversibly links fully turbulent motion to an invariant solution. This precursor of turbulence destabilizes rapidly with Re, and the accompanying explosive increase in attractor dimension effectively marks the transition between deterministic and de facto stochastic dynamics.","lang":"eng"}],"volume":131,"quality_controlled":"1","date_created":"2023-07-24T09:43:59Z","department":[{"_id":"GradSch"},{"_id":"BjHo"}],"external_id":{"pmid":["37540883"],"arxiv":["2306.05098"],"isi":["001052929900004"]},"corr_author":"1","language":[{"iso":"eng"}],"publication_status":"published","main_file_link":[{"url":"https://doi.org/10.48550/arXiv.2306.05098","open_access":"1"}],"pmid":1,"acknowledgement":"We thank Baofang Song as well as the developers of Channelflow for sharing their numerical codes, and Mukund Vasudevan and Holger Kantz for fruitful discussions. This work was supported by a grant from the Simons Foundation (662960, B. H.).","oa":1,"publication_identifier":{"issn":["0031-9007"],"eissn":["1079-7114"]},"scopus_import":"1","publication":"Physical Review Letters","author":[{"full_name":"Paranjape, Chaitanya S","last_name":"Paranjape","first_name":"Chaitanya S","id":"3D85B7C4-F248-11E8-B48F-1D18A9856A87"},{"orcid":"0000-0002-8490-9312","first_name":"Gökhan","id":"66E74FA2-D8BF-11E9-8249-8DE2E5697425","full_name":"Yalniz, Gökhan","last_name":"Yalniz"},{"first_name":"Yohann","full_name":"Duguet, Yohann","last_name":"Duguet"},{"orcid":"0000-0003-0423-5010","full_name":"Budanur, Nazmi B","last_name":"Budanur","id":"3EA1010E-F248-11E8-B48F-1D18A9856A87","first_name":"Nazmi B"},{"last_name":"Hof","full_name":"Hof, Björn","id":"3A374330-F248-11E8-B48F-1D18A9856A87","first_name":"Björn","orcid":"0000-0003-2057-2754"}],"keyword":["General Physics and Astronomy"],"isi":1,"intvolume":"       131"},{"department":[{"_id":"BjHo"}],"external_id":{"pmid":["35061458"],"arxiv":["2111.14894"],"isi":["000748271700010"]},"date_created":"2022-01-23T23:01:28Z","language":[{"iso":"eng"}],"corr_author":"1","publication_status":"published","abstract":[{"lang":"eng","text":"Directed percolation (DP) has recently emerged as a possible solution to the century old puzzle surrounding the transition to turbulence. Multiple model studies reported DP exponents, however, experimental evidence is limited since the largest possible observation times are orders of magnitude shorter than the flows’ characteristic timescales. An exception is cylindrical Couette flow where the limit is not temporal, but rather the realizable system size. We present experiments in a Couette setup of unprecedented azimuthal and axial aspect ratios. Approaching the critical point to within less than 0.1% we determine five critical exponents, all of which are in excellent agreement with the 2+1D DP universality class. The complex dynamics encountered at \r\nthe onset of turbulence can hence be fully rationalized within the framework of statistical mechanics."}],"article_number":"014502","acknowledged_ssus":[{"_id":"M-Shop"}],"volume":128,"quality_controlled":"1","author":[{"first_name":"Lukasz","id":"2C9AF1C2-F248-11E8-B48F-1D18A9856A87","full_name":"Klotz, Lukasz","last_name":"Klotz","orcid":"0000-0003-1740-7635"},{"id":"4787FE80-F248-11E8-B48F-1D18A9856A87","first_name":"Grégoire M","full_name":"Lemoult, Grégoire M","last_name":"Lemoult"},{"last_name":"Avila","full_name":"Avila, Kerstin","first_name":"Kerstin"},{"orcid":"0000-0003-2057-2754","last_name":"Hof","full_name":"Hof, Björn","id":"3A374330-F248-11E8-B48F-1D18A9856A87","first_name":"Björn"}],"publication":"Physical Review Letters","scopus_import":"1","ec_funded":1,"isi":1,"intvolume":"       128","main_file_link":[{"url":"https://arxiv.org/abs/2111.14894","open_access":"1"}],"acknowledgement":"We thank T.Menner, T.Asenov, P. Maier and the Miba machine shop of IST Austria for their valuable support in all technical aspects. We thank Marc Avila for comments on the manuscript. This work was supported by a grant from the Simons Foundation (662960, B.H.). We acknowledge the European Research Council under the European Union’s Seventh Framework Programme (FP/2007-2013)/ERC Grant Agreement 306589 for financial support. K.A.\r\nacknowledges funding from the Central Research Development Fund of the University of Bremen, grant number ZF04B /2019/FB04 Avila Kerstin (”Independent Project for Postdocs”). L.K. was supported by the European Union’s Horizon 2020 Research and innovation programme under the Marie Sklodowska-Curie grant agreement  No. 754411.\r\n","pmid":1,"oa":1,"publication_identifier":{"issn":["0031-9007"],"eissn":["1079-7114"]},"doi":"10.1103/PhysRevLett.128.014502","article_type":"original","arxiv":1,"article_processing_charge":"No","citation":{"mla":"Klotz, Lukasz, et al. “Phase Transition to Turbulence in Spatially Extended Shear Flows.” <i>Physical Review Letters</i>, vol. 128, no. 1, 014502, American Physical Society, 2022, doi:<a href=\"https://doi.org/10.1103/PhysRevLett.128.014502\">10.1103/PhysRevLett.128.014502</a>.","short":"L. Klotz, G.M. Lemoult, K. Avila, B. Hof, Physical Review Letters 128 (2022).","ieee":"L. Klotz, G. M. Lemoult, K. Avila, and B. Hof, “Phase transition to turbulence in spatially extended shear flows,” <i>Physical Review Letters</i>, vol. 128, no. 1. American Physical Society, 2022.","ama":"Klotz L, Lemoult GM, Avila K, Hof B. Phase transition to turbulence in spatially extended shear flows. <i>Physical Review Letters</i>. 2022;128(1). doi:<a href=\"https://doi.org/10.1103/PhysRevLett.128.014502\">10.1103/PhysRevLett.128.014502</a>","apa":"Klotz, L., Lemoult, G. M., Avila, K., &#38; Hof, B. (2022). Phase transition to turbulence in spatially extended shear flows. <i>Physical Review Letters</i>. American Physical Society. <a href=\"https://doi.org/10.1103/PhysRevLett.128.014502\">https://doi.org/10.1103/PhysRevLett.128.014502</a>","chicago":"Klotz, Lukasz, Grégoire M Lemoult, Kerstin Avila, and Björn Hof. “Phase Transition to Turbulence in Spatially Extended Shear Flows.” <i>Physical Review Letters</i>. American Physical Society, 2022. <a href=\"https://doi.org/10.1103/PhysRevLett.128.014502\">https://doi.org/10.1103/PhysRevLett.128.014502</a>.","ista":"Klotz L, Lemoult GM, Avila K, Hof B. 2022. Phase transition to turbulence in spatially extended shear flows. Physical Review Letters. 128(1), 014502."},"_id":"10654","title":"Phase transition to turbulence in spatially extended shear flows","month":"01","user_id":"4359f0d1-fa6c-11eb-b949-802e58b17ae8","project":[{"name":"ISTplus - Postdoctoral Fellowships","call_identifier":"H2020","_id":"260C2330-B435-11E9-9278-68D0E5697425","grant_number":"754411"},{"grant_number":"306589","_id":"25152F3A-B435-11E9-9278-68D0E5697425","name":"Decoding the complexity of turbulence at its origin","call_identifier":"FP7"},{"grant_number":"662960","_id":"238598C6-32DE-11EA-91FC-C7463DDC885E","name":"Revisiting the Turbulence Problem Using Statistical Mechanics"}],"date_published":"2022-01-05T00:00:00Z","oa_version":"Preprint","year":"2022","date_updated":"2024-10-22T11:08:41Z","day":"05","type":"journal_article","publisher":"American Physical Society","issue":"1","status":"public"},{"abstract":[{"lang":"eng","text":"We show that turbulent dynamics that arise in simulations of the three-dimensional Navier--Stokes equations in a triply-periodic domain under sinusoidal forcing can be described as transient visits to the neighborhoods of unstable time-periodic solutions. Based on this description, we reduce the original system with more than 10^5 degrees of freedom to a 17-node Markov chain where each node corresponds to the neighborhood of a periodic orbit. The model accurately reproduces long-term averages of the system's observables as weighted sums over the periodic orbits.\r\n"}],"article_number":"244502","acknowledged_ssus":[{"_id":"ScienComp"}],"volume":126,"quality_controlled":"1","external_id":{"arxiv":["2007.02584"],"isi":["000663310100008"]},"department":[{"_id":"GradSch"},{"_id":"BjHo"}],"date_created":"2021-06-16T15:45:36Z","language":[{"iso":"eng"}],"corr_author":"1","publication_status":"published","main_file_link":[{"url":"https://arxiv.org/abs/2007.02584","open_access":"1"}],"acknowledgement":"We thank the referees for improving this Letter with their comments. We acknowledge stimulating discussions with\r\nH. Edelsbrunner. This work was supported by Grant No. 662960 from the Simons Foundation (B. H.). The numerical calculations were performed at TUBITAK ULAKBIM High Performance and Grid Computing Center (TRUBA resources) and IST Austria High Performance Computing cluster.","publication_identifier":{"issn":["0031-9007"],"eissn":["1079-7114"]},"oa":1,"author":[{"full_name":"Yalniz, Gökhan","last_name":"Yalniz","first_name":"Gökhan","id":"66E74FA2-D8BF-11E9-8249-8DE2E5697425","orcid":"0000-0002-8490-9312"},{"first_name":"Björn","id":"3A374330-F248-11E8-B48F-1D18A9856A87","last_name":"Hof","full_name":"Hof, Björn","orcid":"0000-0003-2057-2754"},{"full_name":"Budanur, Nazmi B","last_name":"Budanur","id":"3EA1010E-F248-11E8-B48F-1D18A9856A87","first_name":"Nazmi B","orcid":"0000-0003-0423-5010"}],"publication":"Physical Review Letters","scopus_import":"1","isi":1,"intvolume":"       126","article_processing_charge":"No","citation":{"short":"G. Yalniz, B. Hof, N.B. Budanur, Physical Review Letters 126 (2021).","mla":"Yalniz, Gökhan, et al. “Coarse Graining the State Space of a Turbulent Flow Using Periodic Orbits.” <i>Physical Review Letters</i>, vol. 126, no. 24, 244502, American Physical Society, 2021, doi:<a href=\"https://doi.org/10.1103/PhysRevLett.126.244502\">10.1103/PhysRevLett.126.244502</a>.","ieee":"G. Yalniz, B. Hof, and N. B. Budanur, “Coarse graining the state space of a turbulent flow using periodic orbits,” <i>Physical Review Letters</i>, vol. 126, no. 24. American Physical Society, 2021.","ama":"Yalniz G, Hof B, Budanur NB. Coarse graining the state space of a turbulent flow using periodic orbits. <i>Physical Review Letters</i>. 2021;126(24). doi:<a href=\"https://doi.org/10.1103/PhysRevLett.126.244502\">10.1103/PhysRevLett.126.244502</a>","apa":"Yalniz, G., Hof, B., &#38; Budanur, N. B. (2021). Coarse graining the state space of a turbulent flow using periodic orbits. <i>Physical Review Letters</i>. American Physical Society. <a href=\"https://doi.org/10.1103/PhysRevLett.126.244502\">https://doi.org/10.1103/PhysRevLett.126.244502</a>","chicago":"Yalniz, Gökhan, Björn Hof, and Nazmi B Budanur. “Coarse Graining the State Space of a Turbulent Flow Using Periodic Orbits.” <i>Physical Review Letters</i>. American Physical Society, 2021. <a href=\"https://doi.org/10.1103/PhysRevLett.126.244502\">https://doi.org/10.1103/PhysRevLett.126.244502</a>.","ista":"Yalniz G, Hof B, Budanur NB. 2021. Coarse graining the state space of a turbulent flow using periodic orbits. Physical Review Letters. 126(24), 244502."},"related_material":{"link":[{"description":"News on IST Homepage","url":"https://ist.ac.at/en/news/turbulent-flow-simplified/","relation":"press_release"}],"record":[{"status":"returned","relation":"popular_science","id":"19591"},{"id":"19684","relation":"dissertation_contains","status":"public"}]},"_id":"9558","title":"Coarse graining the state space of a turbulent flow using periodic orbits","month":"06","doi":"10.1103/PhysRevLett.126.244502","article_type":"letter_note","arxiv":1,"type":"journal_article","day":"18","publisher":"American Physical Society","issue":"24","status":"public","user_id":"4359f0d1-fa6c-11eb-b949-802e58b17ae8","date_published":"2021-06-18T00:00:00Z","project":[{"name":"Revisiting the Turbulence Problem Using Statistical Mechanics","_id":"238598C6-32DE-11EA-91FC-C7463DDC885E","grant_number":"662960"}],"year":"2021","oa_version":"Preprint","date_updated":"2026-04-07T11:47:05Z"}]