[{"author":[{"first_name":"Paulo R","id":"38FCDB4C-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0001-6730-4461","last_name":"Dos Santos Caldas","full_name":"Dos Santos Caldas, Paulo R"},{"last_name":"Lopez Pelegrin","full_name":"Lopez Pelegrin, Maria D","id":"319AA9CE-F248-11E8-B48F-1D18A9856A87","first_name":"Maria D"},{"full_name":"Pearce, Daniel J. G.","last_name":"Pearce","first_name":"Daniel J. G."},{"orcid":"0000-0003-0423-5010","id":"3EA1010E-F248-11E8-B48F-1D18A9856A87","first_name":"Nazmi B","last_name":"Budanur","full_name":"Budanur, Nazmi B"},{"last_name":"Brugués","full_name":"Brugués, Jan","first_name":"Jan"},{"full_name":"Loose, Martin","last_name":"Loose","first_name":"Martin","id":"462D4284-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0001-7309-9724"}],"article_processing_charge":"No","department":[{"_id":"MaLo"},{"_id":"BjHo"}],"date_updated":"2026-04-08T07:26:30Z","status":"public","isi":1,"oa_version":"Published Version","type":"journal_article","doi":"10.1038/s41467-019-13702-4","publication_status":"published","month":"12","user_id":"c635000d-4b10-11ee-a964-aac5a93f6ac1","publication_identifier":{"issn":["2041-1723"]},"acknowledged_ssus":[{"_id":"LifeSc"},{"_id":"Bio"}],"external_id":{"isi":["000503009300001"]},"file":[{"content_type":"application/pdf","creator":"dernst","date_created":"2019-12-23T07:34:56Z","access_level":"open_access","file_id":"7208","file_size":8488733,"checksum":"a1b44b427ba341383197790d0e8789fa","relation":"main_file","file_name":"2019_NatureComm_Caldas.pdf","date_updated":"2020-07-14T12:47:53Z"}],"related_material":{"record":[{"relation":"dissertation_contains","status":"public","id":"8358"}]},"language":[{"iso":"eng"}],"has_accepted_license":"1","article_number":"5744","citation":{"ama":"Dos Santos Caldas PR, Lopez Pelegrin MD, Pearce DJG, Budanur NB, Brugués J, Loose M. Cooperative ordering of treadmilling filaments in cytoskeletal networks of FtsZ and its crosslinker ZapA. <i>Nature Communications</i>. 2019;10. doi:<a href=\"https://doi.org/10.1038/s41467-019-13702-4\">10.1038/s41467-019-13702-4</a>","chicago":"Dos Santos Caldas, Paulo R, Maria D Lopez Pelegrin, Daniel J. G. Pearce, Nazmi B Budanur, Jan Brugués, and Martin Loose. “Cooperative Ordering of Treadmilling Filaments in Cytoskeletal Networks of FtsZ and Its Crosslinker ZapA.” <i>Nature Communications</i>. Springer Nature, 2019. <a href=\"https://doi.org/10.1038/s41467-019-13702-4\">https://doi.org/10.1038/s41467-019-13702-4</a>.","apa":"Dos Santos Caldas, P. R., Lopez Pelegrin, M. D., Pearce, D. J. G., Budanur, N. B., Brugués, J., &#38; Loose, M. (2019). Cooperative ordering of treadmilling filaments in cytoskeletal networks of FtsZ and its crosslinker ZapA. <i>Nature Communications</i>. Springer Nature. <a href=\"https://doi.org/10.1038/s41467-019-13702-4\">https://doi.org/10.1038/s41467-019-13702-4</a>","mla":"Dos Santos Caldas, Paulo R., et al. “Cooperative Ordering of Treadmilling Filaments in Cytoskeletal Networks of FtsZ and Its Crosslinker ZapA.” <i>Nature Communications</i>, vol. 10, 5744, Springer Nature, 2019, doi:<a href=\"https://doi.org/10.1038/s41467-019-13702-4\">10.1038/s41467-019-13702-4</a>.","short":"P.R. Dos Santos Caldas, M.D. Lopez Pelegrin, D.J.G. Pearce, N.B. Budanur, J. Brugués, M. Loose, Nature Communications 10 (2019).","ieee":"P. R. Dos Santos Caldas, M. D. Lopez Pelegrin, D. J. G. Pearce, N. B. Budanur, J. Brugués, and M. Loose, “Cooperative ordering of treadmilling filaments in cytoskeletal networks of FtsZ and its crosslinker ZapA,” <i>Nature Communications</i>, vol. 10. Springer Nature, 2019.","ista":"Dos Santos Caldas PR, Lopez Pelegrin MD, Pearce DJG, Budanur NB, Brugués J, Loose M. 2019. Cooperative ordering of treadmilling filaments in cytoskeletal networks of FtsZ and its crosslinker ZapA. Nature Communications. 10, 5744."},"project":[{"grant_number":"679239","_id":"2595697A-B435-11E9-9278-68D0E5697425","call_identifier":"H2020","name":"Self-Organization of the Bacterial Cell"},{"_id":"260D98C8-B435-11E9-9278-68D0E5697425","name":"Reconstitution of Bacterial Cell Division Using Purified Components"}],"file_date_updated":"2020-07-14T12:47:53Z","corr_author":"1","scopus_import":"1","oa":1,"tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","image":"/images/cc_by.png","short":"CC BY (4.0)"},"year":"2019","date_published":"2019-12-17T00:00:00Z","quality_controlled":"1","intvolume":"        10","date_created":"2019-12-20T12:22:57Z","abstract":[{"lang":"eng","text":"During bacterial cell division, the tubulin-homolog FtsZ forms a ring-like structure at the center of the cell. This Z-ring not only organizes the division machinery, but treadmilling of FtsZ filaments was also found to play a key role in distributing proteins at the division site. What regulates the architecture, dynamics and stability of the Z-ring is currently unknown, but FtsZ-associated proteins are known to play an important role. Here, using an in vitro reconstitution approach, we studied how the well-conserved protein ZapA affects FtsZ treadmilling and filament organization into large-scale patterns. Using high-resolution fluorescence microscopy and quantitative image analysis, we found that ZapA cooperatively increases the spatial order of the filament network, but binds only transiently to FtsZ filaments and has no effect on filament length and treadmilling velocity. Together, our data provides a model for how FtsZ-associated proteins can increase the precision and stability of the bacterial cell division machinery in a switch-like manner."}],"article_type":"original","title":"Cooperative ordering of treadmilling filaments in cytoskeletal networks of FtsZ and its crosslinker ZapA","ec_funded":1,"volume":10,"publication":"Nature Communications","ddc":["570"],"day":"17","publisher":"Springer Nature","_id":"7197"},{"keyword":["Instabilities","Turbulence","Nonlinear dynamics"],"OA_place":"publisher","title":"Onset of turbulence in plane Poiseuille flow","_id":"6957","day":"24","publisher":"Institute of Science and Technology Austria","supervisor":[{"first_name":"Björn","id":"3A374330-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0003-2057-2754","full_name":"Hof, Björn","last_name":"Hof"}],"ddc":["532"],"date_published":"2019-10-24T00:00:00Z","alternative_title":["ISTA Thesis"],"year":"2019","oa":1,"abstract":[{"lang":"eng","text":"In many shear flows like pipe flow, plane Couette flow, plane Poiseuille flow,  etc. turbulence emerges subcritically. Here, when subjected to strong enough perturbations, the flow becomes turbulent in spite of the laminar base flow being linearly stable.  The nature of this instability has puzzled the scientific community for decades. At onset, turbulence appears in localized patches and flows are spatio-temporally intermittent.  In pipe flow the localized turbulent structures are referred to as puffs and in planar flows like plane Couette and channel flow, patches arise in the form of localized oblique bands. In this thesis, we study the onset of turbulence in channel flow in direct numerical simulations from a dynamical system theory perspective, as well as by performing experiments in a large aspect ratio channel.\r\n\r\nThe aim of the experimental work is to determine the critical Reynolds number where turbulence first becomes sustained. Recently, the onset of turbulence has been described in analogy to absorbing state phase transition (i.e. directed percolation). In particular, it has been shown that the critical point can be estimated from the competition between spreading and decay processes. Here, by performing experiments, we identify the mechanisms underlying turbulence proliferation in channel flow and find the critical Reynolds number, above which turbulence becomes sustained. Above the critical point, the continuous growth at the tip of the stripes outweighs the stochastic shedding of turbulent patches at the tail and the stripes expand. For growing stripes, the probability to decay decreases while the probability of stripe splitting increases. Consequently, and unlike for the puffs in pipe flow, neither of these two processes is time-independent i.e. memoryless. Coupling between stripe expansion and creation of new stripes via splitting leads to a significantly lower critical point ($Re_c=670+/-10$) than most earlier studies suggest.  \r\n\r\nWhile the above approach sheds light on how turbulence first becomes sustained, it provides no insight into the origin of the stripes themselves. In the numerical part of the thesis we investigate how turbulent stripes form from invariant solutions of the Navier-Stokes equations. The origin of these turbulent stripes can be identified by applying concepts from the dynamical system theory. In doing so, we identify the exact coherent structures underlying stripes and their bifurcations and how they give rise to the turbulent attractor in phase space. We first report a family of localized nonlinear traveling wave solutions of the Navier-Stokes equations in channel flow. These solutions show structural similarities with turbulent stripes in experiments like obliqueness, quasi-streamwise streaks and vortices, etc. A parametric study of these traveling wave solution is performed, with parameters like Reynolds number, stripe tilt angle and domain size, including the stability of the solutions. These solutions emerge through saddle-node bifurcations and form a phase space skeleton for the turbulent stripes observed in the experiments. The lower branches of these TW solutions at different tilt angles undergo Hopf bifurcation and new solutions branches of relative periodic orbits emerge. These RPO solutions do not belong to the same family and therefore the routes to chaos for different angles are different.  \r\n\r\nIn shear flows, turbulence at onset is transient in nature.  Consequently,turbulence can not be tracked to lower Reynolds numbers, where the dynamics may simplify. Before this happens, turbulence becomes short-lived and laminarizes. In the last part of the thesis, we show that using numerical simulations we can continue turbulent stripes in channel flow past the 'relaminarization barrier' all the way to their origin. Here, turbulent stripe dynamics simplifies and the fluctuations are no longer stochastic and the stripe settles down to a relative periodic orbit. This relative periodic orbit originates from the aforementioned traveling wave solutions. Starting from the relative periodic orbit, a small increase in speed i.e. Reynolds number gives rise to chaos and the attractor dimension sharply increases in contrast to the classical transition scenario where the instabilities affect the flow globally and give rise to much more gradual route to turbulence."}],"date_created":"2019-10-22T12:08:43Z","degree_awarded":"PhD","file":[{"date_created":"2019-10-23T09:54:43Z","access_level":"closed","file_id":"6962","creator":"cparanjape","content_type":"application/zip","file_name":"Chaitanya_Paranjape_source_files_tex_figures.zip","date_updated":"2020-07-14T12:47:46Z","file_size":45828099,"checksum":"7ba298ba0ce7e1d11691af6b8eaf0a0a","relation":"source_file"},{"content_type":"application/pdf","creator":"cparanjape","file_id":"6963","date_created":"2019-10-23T10:37:09Z","access_level":"open_access","checksum":"642697618314e31ac31392da7909c2d9","relation":"main_file","file_size":19504197,"date_updated":"2020-07-14T12:47:46Z","file_name":"Chaitanya_Paranjape_Thesis.pdf"}],"page":"138","publication_identifier":{"eissn":["2663-337X"]},"user_id":"ba8df636-2132-11f1-aed0-ed93e2281fdd","month":"10","file_date_updated":"2020-07-14T12:47:46Z","corr_author":"1","has_accepted_license":"1","citation":{"mla":"Paranjape, Chaitanya S. <i>Onset of Turbulence in Plane Poiseuille Flow</i>. Institute of Science and Technology Austria, 2019, doi:<a href=\"https://doi.org/10.15479/AT:ISTA:6957\">10.15479/AT:ISTA:6957</a>.","ieee":"C. S. Paranjape, “Onset of turbulence in plane Poiseuille flow,” Institute of Science and Technology Austria, 2019.","ista":"Paranjape CS. 2019. Onset of turbulence in plane Poiseuille flow. Institute of Science and Technology Austria.","short":"C.S. Paranjape, Onset of Turbulence in Plane Poiseuille Flow, Institute of Science and Technology Austria, 2019.","chicago":"Paranjape, Chaitanya S. “Onset of Turbulence in Plane Poiseuille Flow.” Institute of Science and Technology Austria, 2019. <a href=\"https://doi.org/10.15479/AT:ISTA:6957\">https://doi.org/10.15479/AT:ISTA:6957</a>.","apa":"Paranjape, C. S. (2019). <i>Onset of turbulence in plane Poiseuille flow</i>. Institute of Science and Technology Austria. <a href=\"https://doi.org/10.15479/AT:ISTA:6957\">https://doi.org/10.15479/AT:ISTA:6957</a>","ama":"Paranjape CS. Onset of turbulence in plane Poiseuille flow. 2019. doi:<a href=\"https://doi.org/10.15479/AT:ISTA:6957\">10.15479/AT:ISTA:6957</a>"},"language":[{"iso":"eng"}],"date_updated":"2026-04-08T07:46:58Z","department":[{"_id":"BjHo"}],"article_processing_charge":"No","author":[{"full_name":"Paranjape, Chaitanya S","last_name":"Paranjape","id":"3D85B7C4-F248-11E8-B48F-1D18A9856A87","first_name":"Chaitanya S"}],"doi":"10.15479/AT:ISTA:6957","publication_status":"published","oa_version":"Published Version","type":"dissertation","status":"public"},{"day":"01","publisher":"Elsevier","arxiv":1,"_id":"6413","publication":"International Journal of Multiphase Flow","title":"Phase-field simulation of core-annular pipe flow","article_type":"original","volume":117,"quality_controlled":"1","main_file_link":[{"url":"https://arxiv.org/abs/1902.07351","open_access":"1"}],"date_created":"2019-05-13T07:58:35Z","abstract":[{"lang":"eng","text":"Phase-field methods have long been used to model the flow of immiscible fluids. Their ability to naturally capture interface topological changes is widely recognized, but their accuracy in simulating flows of real fluids in practical geometries is not established. We here quantitatively investigate the convergence of the phase-field method to the sharp-interface limit with simulations of two-phase pipe flow. We focus on core-annular flows, in which a highly viscous fluid is lubricated by a less viscous fluid, and validate our simulations with an analytic laminar solution, a formal linear stability analysis and also in the fully nonlinear regime. We demonstrate the ability of the phase-field method to accurately deal with non-rectangular geometry, strong advection, unsteady fluctuations and large viscosity contrast. We argue that phase-field methods are very promising for quantitatively studying moderately turbulent flows, especially at high concentrations of the disperse phase."}],"intvolume":"       117","year":"2019","date_published":"2019-08-01T00:00:00Z","oa":1,"scopus_import":"1","language":[{"iso":"eng"}],"citation":{"apa":"Song, B., Plana, C., Lopez Alonso, J. M., &#38; Avila, M. (2019). Phase-field simulation of core-annular pipe flow. <i>International Journal of Multiphase Flow</i>. Elsevier. <a href=\"https://doi.org/10.1016/j.ijmultiphaseflow.2019.04.027\">https://doi.org/10.1016/j.ijmultiphaseflow.2019.04.027</a>","chicago":"Song, Baofang, Carlos Plana, Jose M Lopez Alonso, and Marc Avila. “Phase-Field Simulation of Core-Annular Pipe Flow.” <i>International Journal of Multiphase Flow</i>. Elsevier, 2019. <a href=\"https://doi.org/10.1016/j.ijmultiphaseflow.2019.04.027\">https://doi.org/10.1016/j.ijmultiphaseflow.2019.04.027</a>.","ama":"Song B, Plana C, Lopez Alonso JM, Avila M. Phase-field simulation of core-annular pipe flow. <i>International Journal of Multiphase Flow</i>. 2019;117:14-24. doi:<a href=\"https://doi.org/10.1016/j.ijmultiphaseflow.2019.04.027\">10.1016/j.ijmultiphaseflow.2019.04.027</a>","ieee":"B. Song, C. Plana, J. M. Lopez Alonso, and M. Avila, “Phase-field simulation of core-annular pipe flow,” <i>International Journal of Multiphase Flow</i>, vol. 117. Elsevier, pp. 14–24, 2019.","ista":"Song B, Plana C, Lopez Alonso JM, Avila M. 2019. Phase-field simulation of core-annular pipe flow. International Journal of Multiphase Flow. 117, 14–24.","short":"B. Song, C. Plana, J.M. Lopez Alonso, M. Avila, International Journal of Multiphase Flow 117 (2019) 14–24.","mla":"Song, Baofang, et al. “Phase-Field Simulation of Core-Annular Pipe Flow.” <i>International Journal of Multiphase Flow</i>, vol. 117, Elsevier, 2019, pp. 14–24, doi:<a href=\"https://doi.org/10.1016/j.ijmultiphaseflow.2019.04.027\">10.1016/j.ijmultiphaseflow.2019.04.027</a>."},"publication_identifier":{"issn":["0301-9322"]},"external_id":{"arxiv":["1902.07351"],"isi":["000474496000002"]},"page":"14-24","user_id":"ba8df636-2132-11f1-aed0-ed93e2281fdd","month":"08","oa_version":"Preprint","type":"journal_article","doi":"10.1016/j.ijmultiphaseflow.2019.04.027","publication_status":"published","status":"public","isi":1,"department":[{"_id":"BjHo"}],"date_updated":"2026-04-16T09:49:27Z","author":[{"first_name":"Baofang","last_name":"Song","full_name":"Song, Baofang"},{"first_name":"Carlos","last_name":"Plana","full_name":"Plana, Carlos"},{"first_name":"Jose M","id":"40770848-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0002-0384-2022","full_name":"Lopez Alonso, Jose M","last_name":"Lopez Alonso"},{"first_name":"Marc","last_name":"Avila","full_name":"Avila, Marc"}],"article_processing_charge":"No"},{"publication":"Cell","article_type":"original","title":"Bulk actin dynamics drive phase segregation in zebrafish oocytes","ec_funded":1,"volume":177,"day":"30","publisher":"Elsevier","_id":"6508","pmid":1,"ddc":["570"],"issue":"6","year":"2019","date_published":"2019-05-30T00:00:00Z","oa":1,"quality_controlled":"1","main_file_link":[{"open_access":"1","url":"https://doi.org/10.1016/j.cell.2019.04.030"}],"abstract":[{"lang":"eng","text":"Segregation of maternal determinants within the oocyte constitutes the first step in embryo patterning. In zebrafish oocytes, extensive ooplasmic streaming leads to the segregation of ooplasm from yolk granules along the animal-vegetal axis of the oocyte. Here, we show that this process does not rely on cortical actin reorganization, as previously thought, but instead on a cell-cycle-dependent bulk actin polymerization wave traveling from the animal to the vegetal pole of the oocyte. This wave functions in segregation by both pulling ooplasm animally and pushing yolk granules vegetally. Using biophysical experimentation and theory, we show that ooplasm pulling is mediated by bulk actin network flows exerting friction forces on the ooplasm, while yolk granule pushing is achieved by a mechanism closely resembling actin comet formation on yolk granules. Our study defines a novel role of cell-cycle-controlled bulk actin polymerization waves in oocyte polarization via ooplasmic segregation."}],"intvolume":"       177","date_created":"2019-06-02T21:59:12Z","publication_identifier":{"issn":["0092-8674"],"eissn":["1097-4172"]},"external_id":{"isi":["000469415100013"],"pmid":["31080065"]},"acknowledged_ssus":[{"_id":"Bio"},{"_id":"PreCl"}],"related_material":{"record":[{"id":"8350","relation":"dissertation_contains","status":"public"}],"link":[{"relation":"press_release","url":"https://ist.ac.at/en/news/how-the-cytoplasm-separates-from-the-yolk/","description":"News on IST Homepage"}]},"page":"1463-1479.e18","file":[{"relation":"main_file","checksum":"aea43726d80e35ce3885073a5f05c3e3","file_size":3356292,"file_name":"2019_Cell_Shamipour_accepted.pdf","date_updated":"2020-10-21T07:22:34Z","content_type":"application/pdf","creator":"dernst","file_id":"8686","access_level":"open_access","success":1,"date_created":"2020-10-21T07:22:34Z"}],"acknowledgement":"We would like to thank Pierre Recho, Guillaume Salbreux, and Silvia Grigolon for advice on the theory, Lila Solnica-Krezel for kindly providing us with zebrafish dachsous mutants, members of the Heisenberg and Hannezo groups for fruitful discussions, and the Bioimaging and zebrafish facilities at IST Austria for their continuous support. This project has received funding from the European Union (European Research Council Advanced Grant 742573 to C.P.H.) and from the Austrian Science Fund (FWF) (P 31639 to E.H.).","month":"05","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","file_date_updated":"2020-10-21T07:22:34Z","project":[{"grant_number":"742573","_id":"260F1432-B435-11E9-9278-68D0E5697425","call_identifier":"H2020","name":"Interaction and feedback between cell mechanics and fate specification in vertebrate gastrulation"},{"grant_number":"P31639","_id":"268294B6-B435-11E9-9278-68D0E5697425","call_identifier":"FWF","name":"Active mechano-chemical description of the cell cytoskeleton"}],"scopus_import":"1","language":[{"iso":"eng"}],"has_accepted_license":"1","citation":{"chicago":"Shamipour, Shayan, Roland Kardos, Shi-lei Xue, Björn Hof, Edouard B Hannezo, and Carl-Philipp J Heisenberg. “Bulk Actin Dynamics Drive Phase Segregation in Zebrafish Oocytes.” <i>Cell</i>. Elsevier, 2019. <a href=\"https://doi.org/10.1016/j.cell.2019.04.030\">https://doi.org/10.1016/j.cell.2019.04.030</a>.","apa":"Shamipour, S., Kardos, R., Xue, S., Hof, B., Hannezo, E. B., &#38; Heisenberg, C.-P. J. (2019). Bulk actin dynamics drive phase segregation in zebrafish oocytes. <i>Cell</i>. Elsevier. <a href=\"https://doi.org/10.1016/j.cell.2019.04.030\">https://doi.org/10.1016/j.cell.2019.04.030</a>","ama":"Shamipour S, Kardos R, Xue S, Hof B, Hannezo EB, Heisenberg C-PJ. Bulk actin dynamics drive phase segregation in zebrafish oocytes. <i>Cell</i>. 2019;177(6):1463-1479.e18. doi:<a href=\"https://doi.org/10.1016/j.cell.2019.04.030\">10.1016/j.cell.2019.04.030</a>","mla":"Shamipour, Shayan, et al. “Bulk Actin Dynamics Drive Phase Segregation in Zebrafish Oocytes.” <i>Cell</i>, vol. 177, no. 6, Elsevier, 2019, p. 1463–1479.e18, doi:<a href=\"https://doi.org/10.1016/j.cell.2019.04.030\">10.1016/j.cell.2019.04.030</a>.","short":"S. Shamipour, R. Kardos, S. Xue, B. Hof, E.B. Hannezo, C.-P.J. Heisenberg, Cell 177 (2019) 1463–1479.e18.","ista":"Shamipour S, Kardos R, Xue S, Hof B, Hannezo EB, Heisenberg C-PJ. 2019. Bulk actin dynamics drive phase segregation in zebrafish oocytes. Cell. 177(6), 1463–1479.e18.","ieee":"S. Shamipour, R. Kardos, S. Xue, B. Hof, E. B. Hannezo, and C.-P. J. Heisenberg, “Bulk actin dynamics drive phase segregation in zebrafish oocytes,” <i>Cell</i>, vol. 177, no. 6. Elsevier, p. 1463–1479.e18, 2019."},"department":[{"_id":"CaHe"},{"_id":"EdHa"},{"_id":"BjHo"}],"date_updated":"2026-05-13T22:30:08Z","article_processing_charge":"No","author":[{"first_name":"Shayan","id":"40B34FE2-F248-11E8-B48F-1D18A9856A87","last_name":"Shamipour","full_name":"Shamipour, Shayan"},{"first_name":"Roland","id":"4039350E-F248-11E8-B48F-1D18A9856A87","full_name":"Kardos, Roland","last_name":"Kardos"},{"first_name":"Shi-lei","id":"31D2C804-F248-11E8-B48F-1D18A9856A87","last_name":"Xue","full_name":"Xue, Shi-lei"},{"first_name":"Björn","orcid":"0000-0003-2057-2754","id":"3A374330-F248-11E8-B48F-1D18A9856A87","full_name":"Hof, Björn","last_name":"Hof"},{"orcid":"0000-0001-6005-1561","id":"3A9DB764-F248-11E8-B48F-1D18A9856A87","first_name":"Edouard B","last_name":"Hannezo","full_name":"Hannezo, Edouard B"},{"last_name":"Heisenberg","full_name":"Heisenberg, Carl-Philipp J","first_name":"Carl-Philipp J","id":"39427864-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0002-0912-4566"}],"oa_version":"Published Version","type":"journal_article","doi":"10.1016/j.cell.2019.04.030","publication_status":"published","status":"public","isi":1},{"intvolume":"       179","date_created":"2019-11-12T12:51:06Z","quality_controlled":"1","date_published":"2019-10-31T00:00:00Z","year":"2019","issue":"4","oa":1,"_id":"7001","publisher":"Cell Press","day":"31","ddc":["570"],"pmid":1,"publication":"Cell","volume":179,"ec_funded":1,"article_type":"original","title":"Mechanosensation of tight junctions depends on ZO-1 phase separation and flow","publication_status":"published","doi":"10.1016/j.cell.2019.10.006","type":"journal_article","oa_version":"Submitted Version","isi":1,"status":"public","date_updated":"2026-05-13T22:30:08Z","department":[{"_id":"CaHe"},{"_id":"BjHo"}],"author":[{"orcid":"0000-0001-5130-2226","id":"3436488C-F248-11E8-B48F-1D18A9856A87","first_name":"Cornelia","full_name":"Schwayer, Cornelia","last_name":"Schwayer"},{"full_name":"Shamipour, Shayan","last_name":"Shamipour","id":"40B34FE2-F248-11E8-B48F-1D18A9856A87","first_name":"Shayan"},{"last_name":"Pranjic-Ferscha","full_name":"Pranjic-Ferscha, Kornelija","first_name":"Kornelija","id":"4362B3C2-F248-11E8-B48F-1D18A9856A87"},{"orcid":"0000-0001-7659-9142","id":"30A536BA-F248-11E8-B48F-1D18A9856A87","first_name":"Alexandra","last_name":"Schauer","full_name":"Schauer, Alexandra"},{"first_name":"M","last_name":"Balda","full_name":"Balda, M"},{"first_name":"M","full_name":"Tada, M","last_name":"Tada"},{"first_name":"K","last_name":"Matter","full_name":"Matter, K"},{"orcid":"0000-0002-0912-4566","id":"39427864-F248-11E8-B48F-1D18A9856A87","first_name":"Carl-Philipp J","full_name":"Heisenberg, Carl-Philipp J","last_name":"Heisenberg"}],"article_processing_charge":"No","scopus_import":"1","project":[{"_id":"260F1432-B435-11E9-9278-68D0E5697425","name":"Interaction and feedback between cell mechanics and fate specification in vertebrate gastrulation","call_identifier":"H2020","grant_number":"742573"}],"file_date_updated":"2020-10-21T07:09:45Z","citation":{"mla":"Schwayer, Cornelia, et al. “Mechanosensation of Tight Junctions Depends on ZO-1 Phase Separation and Flow.” <i>Cell</i>, vol. 179, no. 4, Cell Press, 2019, p. 937–952.e18, doi:<a href=\"https://doi.org/10.1016/j.cell.2019.10.006\">10.1016/j.cell.2019.10.006</a>.","ieee":"C. Schwayer <i>et al.</i>, “Mechanosensation of tight junctions depends on ZO-1 phase separation and flow,” <i>Cell</i>, vol. 179, no. 4. Cell Press, p. 937–952.e18, 2019.","ista":"Schwayer C, Shamipour S, Pranjic-Ferscha K, Schauer A, Balda M, Tada M, Matter K, Heisenberg C-PJ. 2019. Mechanosensation of tight junctions depends on ZO-1 phase separation and flow. Cell. 179(4), 937–952.e18.","short":"C. Schwayer, S. Shamipour, K. Pranjic-Ferscha, A. Schauer, M. Balda, M. Tada, K. Matter, C.-P.J. Heisenberg, Cell 179 (2019) 937–952.e18.","ama":"Schwayer C, Shamipour S, Pranjic-Ferscha K, et al. Mechanosensation of tight junctions depends on ZO-1 phase separation and flow. <i>Cell</i>. 2019;179(4):937-952.e18. doi:<a href=\"https://doi.org/10.1016/j.cell.2019.10.006\">10.1016/j.cell.2019.10.006</a>","chicago":"Schwayer, Cornelia, Shayan Shamipour, Kornelija Pranjic-Ferscha, Alexandra Schauer, M Balda, M Tada, K Matter, and Carl-Philipp J Heisenberg. “Mechanosensation of Tight Junctions Depends on ZO-1 Phase Separation and Flow.” <i>Cell</i>. Cell Press, 2019. <a href=\"https://doi.org/10.1016/j.cell.2019.10.006\">https://doi.org/10.1016/j.cell.2019.10.006</a>.","apa":"Schwayer, C., Shamipour, S., Pranjic-Ferscha, K., Schauer, A., Balda, M., Tada, M., … Heisenberg, C.-P. J. (2019). Mechanosensation of tight junctions depends on ZO-1 phase separation and flow. <i>Cell</i>. Cell Press. <a href=\"https://doi.org/10.1016/j.cell.2019.10.006\">https://doi.org/10.1016/j.cell.2019.10.006</a>"},"has_accepted_license":"1","language":[{"iso":"eng"}],"related_material":{"link":[{"relation":"press_release","url":"https://ist.ac.at/en/news/biochemistry-meets-mechanics-the-sensitive-nature-of-cell-cell-contact-formation-in-embryo-development/","description":"News auf IST Website"}],"record":[{"id":"7186","status":"public","relation":"dissertation_contains"},{"status":"public","relation":"dissertation_contains","id":"8350"}]},"page":"937-952.e18","file":[{"file_size":8805878,"relation":"main_file","checksum":"33dac4bb77ee630e2666e936b4d57980","date_updated":"2020-10-21T07:09:45Z","file_name":"2019_Cell_Schwayer_accepted.pdf","content_type":"application/pdf","creator":"dernst","access_level":"open_access","success":1,"date_created":"2020-10-21T07:09:45Z","file_id":"8684"}],"acknowledged_ssus":[{"_id":"PreCl"},{"_id":"Bio"}],"external_id":{"pmid":["31675500"],"isi":["000493898000012"]},"publication_identifier":{"issn":["0092-8674"],"eissn":["1097-4172"]},"month":"10","user_id":"4359f0d1-fa6c-11eb-b949-802e58b17ae8"},{"project":[{"grant_number":"306589","name":"Decoding the complexity of turbulence at its origin","_id":"25152F3A-B435-11E9-9278-68D0E5697425","call_identifier":"FP7"}],"scopus_import":"1","language":[{"iso":"eng"}],"citation":{"mla":"Kühnen, Jakob, et al. “Relaminarization of Pipe Flow by Means of 3D-Printed Shaped Honeycombs.” <i>Journal of Fluids Engineering</i>, vol. 141, no. 11, 111105, ASME, 2019, doi:<a href=\"https://doi.org/10.1115/1.4043494\">10.1115/1.4043494</a>.","short":"J. Kühnen, D. Scarselli, B. Hof, Journal of Fluids Engineering 141 (2019).","ieee":"J. Kühnen, D. Scarselli, and B. Hof, “Relaminarization of pipe flow by means of 3D-printed shaped honeycombs,” <i>Journal of Fluids Engineering</i>, vol. 141, no. 11. ASME, 2019.","ista":"Kühnen J, Scarselli D, Hof B. 2019. Relaminarization of pipe flow by means of 3D-printed shaped honeycombs. Journal of Fluids Engineering. 141(11), 111105.","ama":"Kühnen J, Scarselli D, Hof B. Relaminarization of pipe flow by means of 3D-printed shaped honeycombs. <i>Journal of Fluids Engineering</i>. 2019;141(11). doi:<a href=\"https://doi.org/10.1115/1.4043494\">10.1115/1.4043494</a>","chicago":"Kühnen, Jakob, Davide Scarselli, and Björn Hof. “Relaminarization of Pipe Flow by Means of 3D-Printed Shaped Honeycombs.” <i>Journal of Fluids Engineering</i>. ASME, 2019. <a href=\"https://doi.org/10.1115/1.4043494\">https://doi.org/10.1115/1.4043494</a>.","apa":"Kühnen, J., Scarselli, D., &#38; Hof, B. (2019). Relaminarization of pipe flow by means of 3D-printed shaped honeycombs. <i>Journal of Fluids Engineering</i>. ASME. <a href=\"https://doi.org/10.1115/1.4043494\">https://doi.org/10.1115/1.4043494</a>"},"article_number":"111105","publication_identifier":{"eissn":["1528-901X"],"issn":["0098-2202"]},"related_material":{"record":[{"status":"public","relation":"dissertation_contains","id":"7258"}]},"acknowledged_ssus":[{"_id":"M-Shop"}],"external_id":{"arxiv":["1809.07625"],"isi":["000487748600005"]},"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","month":"11","type":"journal_article","oa_version":"Preprint","publication_status":"published","doi":"10.1115/1.4043494","status":"public","isi":1,"department":[{"_id":"BjHo"}],"date_updated":"2026-05-13T22:30:53Z","article_processing_charge":"No","author":[{"last_name":"Kühnen","full_name":"Kühnen, Jakob","first_name":"Jakob","orcid":"0000-0003-4312-0179","id":"3A47AE32-F248-11E8-B48F-1D18A9856A87"},{"last_name":"Scarselli","full_name":"Scarselli, Davide","first_name":"Davide","orcid":"0000-0001-5227-4271","id":"40315C30-F248-11E8-B48F-1D18A9856A87"},{"first_name":"Björn","orcid":"0000-0003-2057-2754","id":"3A374330-F248-11E8-B48F-1D18A9856A87","full_name":"Hof, Björn","last_name":"Hof"}],"publisher":"ASME","arxiv":1,"day":"01","_id":"6486","publication":"Journal of Fluids Engineering","ec_funded":1,"title":"Relaminarization of pipe flow by means of 3D-printed shaped honeycombs","article_type":"original","volume":141,"quality_controlled":"1","abstract":[{"text":"Based on a novel control scheme, where a steady modification of the streamwise velocity profile leads to complete relaminarization of initially fully turbulent pipe flow, we investigate the applicability and usefulness of custom-shaped honeycombs for such control. The custom-shaped honeycombs are used as stationary flow management devices which generate specific modifications of the streamwise velocity profile. Stereoscopic particle image velocimetry and pressure drop measurements are used to investigate and capture the development of the relaminarizing flow downstream these devices. We compare the performance of straight (constant length across the radius of the pipe) honeycombs with custom-shaped ones (variable length across the radius) and try to determine the optimal shape for maximal relaminarization at minimal pressure loss. The optimally modified streamwise velocity profile is found to be M-shaped, and the maximum attainable Reynolds number for total relaminarization is found to be of the order of 10,000. Consequently, the respective reduction in skin friction downstream of the device is almost by a factor of 5. The break-even point, where the additional pressure drop caused by the device is balanced by the savings due to relaminarization and a net gain is obtained, corresponds to a downstream stretch of distances as low as approximately 100 pipe diameters of laminar flow.","lang":"eng"}],"date_created":"2019-05-26T21:59:13Z","intvolume":"       141","main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/1809.07625"}],"year":"2019","issue":"11","date_published":"2019-11-01T00:00:00Z","oa":1},{"volume":867,"title":"Relaminarising pipe flow by wall movement","ec_funded":1,"publication":"Journal of Fluid Mechanics","_id":"6228","day":"25","arxiv":1,"publisher":"Cambridge University Press","oa":1,"date_published":"2019-05-25T00:00:00Z","year":"2019","main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/1807.05357"}],"abstract":[{"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.","lang":"eng"}],"intvolume":"       867","date_created":"2019-04-07T21:59:14Z","quality_controlled":"1","month":"05","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","external_id":{"arxiv":["1807.05357"],"isi":["000462606100001"]},"page":"934-948","related_material":{"record":[{"relation":"dissertation_contains","status":"public","id":"7258"}],"link":[{"url":"https://doi.org/10.1017/jfm.2019.191","relation":"supplementary_material"}]},"publication_identifier":{"eissn":["1469-7645"],"issn":["0022-1120"]},"citation":{"short":"D. Scarselli, J. Kühnen, B. Hof, Journal of Fluid Mechanics 867 (2019) 934–948.","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.","ista":"Scarselli D, Kühnen J, Hof B. 2019. Relaminarising pipe flow by wall movement. Journal of Fluid Mechanics. 867, 934–948.","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>.","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>","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>.","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>"},"language":[{"iso":"eng"}],"scopus_import":"1","project":[{"grant_number":"306589","call_identifier":"FP7","_id":"25152F3A-B435-11E9-9278-68D0E5697425","name":"Decoding the complexity of turbulence at its origin"},{"grant_number":"737549","call_identifier":"H2020","_id":"25104D44-B435-11E9-9278-68D0E5697425","name":"Eliminating turbulence in oil pipelines"}],"article_processing_charge":"No","author":[{"id":"40315C30-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0001-5227-4271","first_name":"Davide","full_name":"Scarselli, Davide","last_name":"Scarselli"},{"orcid":"0000-0003-4312-0179","id":"3A47AE32-F248-11E8-B48F-1D18A9856A87","first_name":"Jakob","full_name":"Kühnen, Jakob","last_name":"Kühnen"},{"full_name":"Hof, Björn","last_name":"Hof","first_name":"Björn","id":"3A374330-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0003-2057-2754"}],"date_updated":"2026-05-13T22:30:52Z","department":[{"_id":"BjHo"}],"isi":1,"status":"public","doi":"10.1017/jfm.2019.191","publication_status":"published","oa_version":"Preprint","type":"journal_article"},{"date_created":"2019-03-31T21:59:12Z","abstract":[{"lang":"eng","text":"Suspended particles can alter the properties of fluids and in particular also affect the transition fromlaminar to turbulent flow. An earlier study [Mataset al.,Phys. Rev. Lett.90, 014501 (2003)] reported howthe subcritical (i.e., hysteretic) transition to turbulent puffs is affected by the addition of particles. Here weshow that in addition to this known transition, with increasing concentration a supercritical (i.e.,continuous) transition to a globally fluctuating state is found. At the same time the Newtonian-typetransition to puffs is delayed to larger Reynolds numbers. At even higher concentration only the globallyfluctuating state is found. The dynamics of particle laden flows are hence determined by two competinginstabilities that give rise to three flow regimes: Newtonian-type turbulence at low, a particle inducedglobally fluctuating state at high, and a coexistence state at intermediate concentrations."}],"intvolume":"       122","main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/1809.06358"}],"quality_controlled":"1","oa":1,"date_published":"2019-03-22T00:00:00Z","year":"2019","issue":"11","pmid":1,"_id":"6189","arxiv":1,"publisher":"American Physical Society","day":"22","volume":122,"title":"Transition to turbulence in particle laden flows","publication":"Physical Review Letters","isi":1,"status":"public","publication_status":"published","doi":"10.1103/PhysRevLett.122.114502","type":"journal_article","oa_version":"Preprint","article_processing_charge":"No","author":[{"id":"469E6004-F248-11E8-B48F-1D18A9856A87","first_name":"Nishchal","full_name":"Agrawal, Nishchal","last_name":"Agrawal"},{"id":"448BD5BC-F248-11E8-B48F-1D18A9856A87","first_name":"George H","last_name":"Choueiri","full_name":"Choueiri, George H"},{"last_name":"Hof","full_name":"Hof, Björn","first_name":"Björn","orcid":"0000-0003-2057-2754","id":"3A374330-F248-11E8-B48F-1D18A9856A87"}],"date_updated":"2026-05-13T22:31:10Z","department":[{"_id":"BjHo"}],"citation":{"chicago":"Agrawal, Nishchal, George H Choueiri, and Björn Hof. “Transition to Turbulence in Particle Laden Flows.” <i>Physical Review Letters</i>. American Physical Society, 2019. <a href=\"https://doi.org/10.1103/PhysRevLett.122.114502\">https://doi.org/10.1103/PhysRevLett.122.114502</a>.","apa":"Agrawal, N., Choueiri, G. H., &#38; Hof, B. (2019). Transition to turbulence in particle laden flows. <i>Physical Review Letters</i>. American Physical Society. <a href=\"https://doi.org/10.1103/PhysRevLett.122.114502\">https://doi.org/10.1103/PhysRevLett.122.114502</a>","ama":"Agrawal N, Choueiri GH, Hof B. Transition to turbulence in particle laden flows. <i>Physical Review Letters</i>. 2019;122(11). doi:<a href=\"https://doi.org/10.1103/PhysRevLett.122.114502\">10.1103/PhysRevLett.122.114502</a>","mla":"Agrawal, Nishchal, et al. “Transition to Turbulence in Particle Laden Flows.” <i>Physical Review Letters</i>, vol. 122, no. 11, 114502, American Physical Society, 2019, doi:<a href=\"https://doi.org/10.1103/PhysRevLett.122.114502\">10.1103/PhysRevLett.122.114502</a>.","short":"N. Agrawal, G.H. Choueiri, B. Hof, Physical Review Letters 122 (2019).","ieee":"N. Agrawal, G. H. Choueiri, and B. Hof, “Transition to turbulence in particle laden flows,” <i>Physical Review Letters</i>, vol. 122, no. 11. American Physical Society, 2019.","ista":"Agrawal N, Choueiri GH, Hof B. 2019. Transition to turbulence in particle laden flows. Physical Review Letters. 122(11), 114502."},"article_number":"114502","language":[{"iso":"eng"}],"scopus_import":"1","user_id":"ba8df636-2132-11f1-aed0-ed93e2281fdd","month":"03","related_material":{"record":[{"id":"9728","status":"public","relation":"dissertation_contains"}]},"external_id":{"isi":["000461922000006"],"pmid":["30951357"],"arxiv":["1809.06358"]},"publication_identifier":{"issn":["0031-9007"],"eissn":["1079-7114"]}},{"date_updated":"2023-09-11T12:45:44Z","department":[{"_id":"BjHo"}],"article_processing_charge":"No","author":[{"orcid":"0000-0003-0423-5010","id":"3EA1010E-F248-11E8-B48F-1D18A9856A87","first_name":"Nazmi B","last_name":"Budanur","full_name":"Budanur, Nazmi B"},{"last_name":"Hof","full_name":"Hof, Björn","first_name":"Björn","orcid":"0000-0003-2057-2754","id":"3A374330-F248-11E8-B48F-1D18A9856A87"}],"doi":"10.1103/PhysRevFluids.3.054401","publication_status":"published","oa_version":"Preprint","type":"journal_article","isi":1,"status":"public","external_id":{"arxiv":["1802.01918"],"isi":["000433426200001"]},"user_id":"c635000d-4b10-11ee-a964-aac5a93f6ac1","month":"05","scopus_import":"1","article_number":"054401","citation":{"ieee":"N. B. Budanur and B. Hof, “Complexity of the laminar-turbulent boundary in pipe flow,” <i>Physical Review Fluids</i>, vol. 3, no. 5. American Physical Society, 2018.","ista":"Budanur NB, Hof B. 2018. Complexity of the laminar-turbulent boundary in pipe flow. Physical Review Fluids. 3(5), 054401.","short":"N.B. Budanur, B. Hof, Physical Review Fluids 3 (2018).","mla":"Budanur, Nazmi B., and Björn Hof. “Complexity of the Laminar-Turbulent Boundary in Pipe Flow.” <i>Physical Review Fluids</i>, vol. 3, no. 5, 054401, American Physical Society, 2018, doi:<a href=\"https://doi.org/10.1103/PhysRevFluids.3.054401\">10.1103/PhysRevFluids.3.054401</a>.","ama":"Budanur NB, Hof B. Complexity of the laminar-turbulent boundary in pipe flow. <i>Physical Review Fluids</i>. 2018;3(5). doi:<a href=\"https://doi.org/10.1103/PhysRevFluids.3.054401\">10.1103/PhysRevFluids.3.054401</a>","apa":"Budanur, N. B., &#38; Hof, B. (2018). Complexity of the laminar-turbulent boundary in pipe flow. <i>Physical Review Fluids</i>. American Physical Society. <a href=\"https://doi.org/10.1103/PhysRevFluids.3.054401\">https://doi.org/10.1103/PhysRevFluids.3.054401</a>","chicago":"Budanur, Nazmi B, and Björn Hof. “Complexity of the Laminar-Turbulent Boundary in Pipe Flow.” <i>Physical Review Fluids</i>. American Physical Society, 2018. <a href=\"https://doi.org/10.1103/PhysRevFluids.3.054401\">https://doi.org/10.1103/PhysRevFluids.3.054401</a>."},"language":[{"iso":"eng"}],"date_published":"2018-05-30T00:00:00Z","issue":"5","year":"2018","oa":1,"main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/1802.01918"}],"intvolume":"         3","date_created":"2018-12-11T11:45:39Z","abstract":[{"text":"Over the past decade, the edge of chaos has proven to be a fruitful starting point for investigations of shear flows when the laminar base flow is linearly stable. Numerous computational studies of shear flows demonstrated the existence of states that separate laminar and turbulent regions of the state space. In addition, some studies determined invariant solutions that reside on this edge. In this paper, we study the unstable manifold of one such solution with the aid of continuous symmetry reduction, which we formulate here for the simultaneous quotiening of axial and azimuthal symmetries. Upon our investigation of the unstable manifold, we discover a previously unknown traveling-wave solution on the laminar-turbulent boundary with a relatively complex structure. By means of low-dimensional projections, we visualize different dynamical paths that connect these solutions to the turbulence. Our numerical experiments demonstrate that the laminar-turbulent boundary exhibits qualitatively different regions whose properties are influenced by the nearby invariant solutions.","lang":"eng"}],"quality_controlled":"1","publication":"Physical Review Fluids","volume":3,"publist_id":"7590","title":"Complexity of the laminar-turbulent boundary in pipe flow","_id":"291","day":"30","publisher":"American Physical Society","arxiv":1},{"month":"03","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","acknowledgement":"The authors thank Philipp Maier and the IST Austria workshop for their dedicated technical support.","external_id":{"isi":["000427804000005"],"arxiv":["1703.06271"]},"acknowledged_ssus":[{"_id":"SSU"}],"citation":{"ama":"Choueiri GH, Lopez Alonso JM, Hof B. Exceeding the asymptotic limit of polymer drag reduction. <i>Physical Review Letters</i>. 2018;120(12). doi:<a href=\"https://doi.org/10.1103/PhysRevLett.120.124501\">10.1103/PhysRevLett.120.124501</a>","apa":"Choueiri, G. H., Lopez Alonso, J. M., &#38; Hof, B. (2018). Exceeding the asymptotic limit of polymer drag reduction. <i>Physical Review Letters</i>. American Physical Society. <a href=\"https://doi.org/10.1103/PhysRevLett.120.124501\">https://doi.org/10.1103/PhysRevLett.120.124501</a>","chicago":"Choueiri, George H, Jose M Lopez Alonso, and Björn Hof. “Exceeding the Asymptotic Limit of Polymer Drag Reduction.” <i>Physical Review Letters</i>. American Physical Society, 2018. <a href=\"https://doi.org/10.1103/PhysRevLett.120.124501\">https://doi.org/10.1103/PhysRevLett.120.124501</a>.","short":"G.H. Choueiri, J.M. Lopez Alonso, B. Hof, Physical Review Letters 120 (2018).","ieee":"G. H. Choueiri, J. M. Lopez Alonso, and B. Hof, “Exceeding the asymptotic limit of polymer drag reduction,” <i>Physical Review Letters</i>, vol. 120, no. 12. American Physical Society, 2018.","ista":"Choueiri GH, Lopez Alonso JM, Hof B. 2018. Exceeding the asymptotic limit of polymer drag reduction. Physical Review Letters. 120(12), 124501.","mla":"Choueiri, George H., et al. “Exceeding the Asymptotic Limit of Polymer Drag Reduction.” <i>Physical Review Letters</i>, vol. 120, no. 12, 124501, American Physical Society, 2018, doi:<a href=\"https://doi.org/10.1103/PhysRevLett.120.124501\">10.1103/PhysRevLett.120.124501</a>."},"article_number":"124501","language":[{"iso":"eng"}],"scopus_import":"1","corr_author":"1","project":[{"grant_number":"291734","_id":"25681D80-B435-11E9-9278-68D0E5697425","call_identifier":"FP7","name":"International IST Postdoc Fellowship Programme"},{"call_identifier":"FP7","name":"Decoding the complexity of turbulence at its origin","_id":"25152F3A-B435-11E9-9278-68D0E5697425","grant_number":"306589"}],"article_processing_charge":"No","author":[{"last_name":"Choueiri","full_name":"Choueiri, George H","first_name":"George H","id":"448BD5BC-F248-11E8-B48F-1D18A9856A87"},{"id":"40770848-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0002-0384-2022","first_name":"Jose M","last_name":"Lopez Alonso","full_name":"Lopez Alonso, Jose M"},{"full_name":"Hof, Björn","last_name":"Hof","id":"3A374330-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0003-2057-2754","first_name":"Björn"}],"date_updated":"2025-06-04T07:52:00Z","department":[{"_id":"BjHo"}],"isi":1,"status":"public","publication_status":"published","doi":"10.1103/PhysRevLett.120.124501","type":"journal_article","oa_version":"Preprint","publist_id":"7537","volume":120,"ec_funded":1,"title":"Exceeding the asymptotic limit of polymer drag reduction","publication":"Physical Review Letters","_id":"328","publisher":"American Physical Society","arxiv":1,"day":"19","oa":1,"date_published":"2018-03-19T00:00:00Z","year":"2018","issue":"12","date_created":"2018-12-11T11:45:51Z","intvolume":"       120","abstract":[{"text":"The drag of turbulent flows can be drastically decreased by adding small amounts of high molecular weight polymers. While drag reduction initially increases with polymer concentration, it eventually saturates to what is known as the maximum drag reduction (MDR) asymptote; this asymptote is generally attributed to the dynamics being reduced to a marginal yet persistent state of subdued turbulent motion. Contrary to this accepted view, we show that, for an appropriate choice of parameters, polymers can reduce the drag beyond the suggested asymptotic limit, eliminating turbulence and giving way to laminar flow. At higher polymer concentrations, however, the laminar state becomes unstable, resulting in a fluctuating flow with the characteristic drag of the MDR asymptote. Our findings indicate that the asymptotic state is hence dynamically disconnected from ordinary turbulence. © 2018 American Physical Society.","lang":"eng"}],"main_file_link":[{"url":"https://arxiv.org/abs/1703.06271","open_access":"1"}],"quality_controlled":"1"},{"main_file_link":[{"url":"https://arxiv.org/abs/1808.02088","open_access":"1"}],"intvolume":"        98","date_created":"2018-12-11T11:44:49Z","abstract":[{"lang":"eng","text":"Recent studies suggest that unstable, nonchaotic solutions of the Navier-Stokes equation may provide deep insights into fluid turbulence. In this article, we present a combined experimental and numerical study exploring the dynamical role of unstable equilibrium solutions and their invariant manifolds in a weakly turbulent, electromagnetically driven, shallow fluid layer. Identifying instants when turbulent evolution slows down, we compute 31 unstable equilibria of a realistic two-dimensional model of the flow. We establish the dynamical relevance of these unstable equilibria by showing that they are closely visited by the turbulent flow. We also establish the dynamical relevance of unstable manifolds by verifying that they are shadowed by turbulent trajectories departing from the neighborhoods of unstable equilibria over large distances in state space."}],"quality_controlled":"1","date_published":"2018-08-13T00:00:00Z","issue":"2","year":"2018","oa":1,"_id":"136","day":"13","arxiv":1,"publisher":"American Physical Society","publication":"Physical Review E","volume":98,"title":"Unstable equilibria and invariant manifolds in quasi-two-dimensional Kolmogorov-like flow","doi":"10.1103/PhysRevE.98.023105","publication_status":"published","oa_version":"Submitted Version","type":"journal_article","isi":1,"status":"public","date_updated":"2023-10-10T13:29:10Z","department":[{"_id":"BjHo"}],"author":[{"last_name":"Suri","full_name":"Suri, Balachandra","id":"47A5E706-F248-11E8-B48F-1D18A9856A87","first_name":"Balachandra"},{"first_name":"Jeffrey","full_name":"Tithof, Jeffrey","last_name":"Tithof"},{"full_name":"Grigoriev, Roman","last_name":"Grigoriev","first_name":"Roman"},{"first_name":"Michael","last_name":"Schatz","full_name":"Schatz, Michael"}],"article_processing_charge":"No","scopus_import":"1","citation":{"short":"B. Suri, J. Tithof, R. Grigoriev, M. Schatz, Physical Review E 98 (2018).","ista":"Suri B, Tithof J, Grigoriev R, Schatz M. 2018. Unstable equilibria and invariant manifolds in quasi-two-dimensional Kolmogorov-like flow. Physical Review E. 98(2).","ieee":"B. Suri, J. Tithof, R. Grigoriev, and M. Schatz, “Unstable equilibria and invariant manifolds in quasi-two-dimensional Kolmogorov-like flow,” <i>Physical Review E</i>, vol. 98, no. 2. American Physical Society, 2018.","mla":"Suri, Balachandra, et al. “Unstable Equilibria and Invariant Manifolds in Quasi-Two-Dimensional Kolmogorov-like Flow.” <i>Physical Review E</i>, vol. 98, no. 2, American Physical Society, 2018, doi:<a href=\"https://doi.org/10.1103/PhysRevE.98.023105\">10.1103/PhysRevE.98.023105</a>.","ama":"Suri B, Tithof J, Grigoriev R, Schatz M. Unstable equilibria and invariant manifolds in quasi-two-dimensional Kolmogorov-like flow. <i>Physical Review E</i>. 2018;98(2). doi:<a href=\"https://doi.org/10.1103/PhysRevE.98.023105\">10.1103/PhysRevE.98.023105</a>","apa":"Suri, B., Tithof, J., Grigoriev, R., &#38; Schatz, M. (2018). Unstable equilibria and invariant manifolds in quasi-two-dimensional Kolmogorov-like flow. <i>Physical Review E</i>. American Physical Society. <a href=\"https://doi.org/10.1103/PhysRevE.98.023105\">https://doi.org/10.1103/PhysRevE.98.023105</a>","chicago":"Suri, Balachandra, Jeffrey Tithof, Roman Grigoriev, and Michael Schatz. “Unstable Equilibria and Invariant Manifolds in Quasi-Two-Dimensional Kolmogorov-like Flow.” <i>Physical Review E</i>. American Physical Society, 2018. <a href=\"https://doi.org/10.1103/PhysRevE.98.023105\">https://doi.org/10.1103/PhysRevE.98.023105</a>."},"language":[{"iso":"eng"}],"external_id":{"arxiv":["1808.02088"],"isi":["000441466800010"]},"month":"08","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87"},{"isi":1,"status":"public","publication_status":"published","doi":"10.1103/PhysRevFluids.3.103303","type":"journal_article","oa_version":"Submitted Version","article_processing_charge":"No","author":[{"orcid":"0000-0002-3072-5999","id":"2A2006B2-F248-11E8-B48F-1D18A9856A87","first_name":"Atul","full_name":"Varshney, Atul","last_name":"Varshney"},{"last_name":"Steinberg","full_name":"Steinberg, Victor","first_name":"Victor"}],"date_updated":"2025-04-14T07:44:02Z","department":[{"_id":"BjHo"}],"citation":{"ista":"Varshney A, Steinberg V. 2018. Mixing layer instability and vorticity amplification in a creeping viscoelastic flow. Physical Review Fluids. 3(10), 103303.","ieee":"A. Varshney and V. Steinberg, “Mixing layer instability and vorticity amplification in a creeping viscoelastic flow,” <i>Physical Review Fluids</i>, vol. 3, no. 10. American Physical Society, 2018.","short":"A. Varshney, V. Steinberg, Physical Review Fluids 3 (2018).","mla":"Varshney, Atul, and Victor Steinberg. “Mixing Layer Instability and Vorticity Amplification in a Creeping Viscoelastic Flow.” <i>Physical Review Fluids</i>, vol. 3, no. 10, 103303, American Physical Society, 2018, doi:<a href=\"https://doi.org/10.1103/PhysRevFluids.3.103303\">10.1103/PhysRevFluids.3.103303</a>.","apa":"Varshney, A., &#38; Steinberg, V. (2018). Mixing layer instability and vorticity amplification in a creeping viscoelastic flow. <i>Physical Review Fluids</i>. American Physical Society. <a href=\"https://doi.org/10.1103/PhysRevFluids.3.103303\">https://doi.org/10.1103/PhysRevFluids.3.103303</a>","chicago":"Varshney, Atul, and Victor Steinberg. “Mixing Layer Instability and Vorticity Amplification in a Creeping Viscoelastic Flow.” <i>Physical Review Fluids</i>. American Physical Society, 2018. <a href=\"https://doi.org/10.1103/PhysRevFluids.3.103303\">https://doi.org/10.1103/PhysRevFluids.3.103303</a>.","ama":"Varshney A, Steinberg V. Mixing layer instability and vorticity amplification in a creeping viscoelastic flow. <i>Physical Review Fluids</i>. 2018;3(10). doi:<a href=\"https://doi.org/10.1103/PhysRevFluids.3.103303\">10.1103/PhysRevFluids.3.103303</a>"},"article_number":"103303","has_accepted_license":"1","pubrep_id":"1062","language":[{"iso":"eng"}],"scopus_import":"1","file_date_updated":"2020-07-14T12:45:04Z","project":[{"name":"ISTplus - Postdoctoral Fellowships","call_identifier":"H2020","_id":"260C2330-B435-11E9-9278-68D0E5697425","grant_number":"754411"}],"user_id":"c635000d-4b10-11ee-a964-aac5a93f6ac1","month":"10","file":[{"date_updated":"2020-07-14T12:45:04Z","file_name":"IST-2018-1062-v1+1_PhysRevFluids.3.103303.pdf","relation":"main_file","checksum":"7fc0a2322214d1c04debef36d5bf2e8a","file_size":1838431,"file_id":"5043","access_level":"open_access","date_created":"2018-12-12T10:13:56Z","content_type":"application/pdf","creator":"system"}],"acknowledgement":"This work was partially supported by the Israel Science Foundation (ISF; Grant No. 882/15) and the Binational USA-Israel Foundation (BSF; Grant No. 2016145).","external_id":{"isi":["000447469200001"]},"abstract":[{"text":"We report quantitative evidence of mixing-layer elastic instability in a viscoelastic fluid flow between two widely spaced obstacles hindering a channel flow at Re 1 and Wi 1. Two mixing layers with nonuniform shear velocity profiles are formed in the region between the obstacles. The mixing-layer instability arises in the vicinity of an inflection point on the shear velocity profile with a steep variation in the elastic stress. The instability results in an intermittent appearance of small vortices in the mixing layers and an amplification of spatiotemporal averaged vorticity in the elastic turbulence regime. The latter is characterized through scaling of friction factor with Wi and both pressure and velocity spectra. Furthermore, the observations reported provide improved understanding of the stability of the mixing layer in a viscoelastic fluid at large elasticity, i.e., Wi 1 and Re 1 and oppose the current view of suppression of vorticity solely by polymer additives.","lang":"eng"}],"date_created":"2018-12-11T11:44:10Z","intvolume":"         3","quality_controlled":"1","oa":1,"date_published":"2018-10-16T00:00:00Z","year":"2018","issue":"10","ddc":["532"],"_id":"16","publisher":"American Physical Society","day":"16","volume":3,"publist_id":"8039","ec_funded":1,"title":"Mixing layer instability and vorticity amplification in a creeping viscoelastic flow","article_type":"original","publication":"Physical Review Fluids"},{"abstract":[{"lang":"eng","text":"Creeping flow of polymeric fluid without inertia exhibits elastic instabilities and elastic turbulence accompanied by drag enhancement due to elastic stress produced by flow-stretched polymers. However, in inertia-dominated flow at high Re and low fluid elasticity El, a reduction in turbulent frictional drag is caused by an intricate competition between inertial and elastic stresses. Here we explore the effect of inertia on the stability of viscoelastic flow in a broad range of control parameters El and (Re,Wi). We present the stability diagram of observed flow regimes in Wi-Re coordinates and find that the instabilities' onsets show an unexpectedly nonmonotonic dependence on El. Further, three distinct regions in the diagram are identified based on El. Strikingly, for high-elasticity fluids we discover a complete relaminarization of flow at Reynolds number in the range of 1 to 10, different from a well-known turbulent drag reduction. These counterintuitive effects may be explained by a finite polymer extensibility and a suppression of vorticity at high Wi. Our results call for further theoretical and numerical development to uncover the role of inertial effect on elastic turbulence in a viscoelastic flow."}],"intvolume":"         3","date_created":"2018-12-11T11:44:11Z","quality_controlled":"1","date_published":"2018-10-15T00:00:00Z","year":"2018","issue":"10","oa":1,"_id":"17","publisher":"American Physical Society","day":"15","ddc":["532"],"publication":"Physical Review Fluids","publist_id":"8038","volume":3,"ec_funded":1,"title":"Drag enhancement and drag reduction in viscoelastic flow","publication_status":"published","doi":"10.1103/PhysRevFluids.3.103302","type":"journal_article","oa_version":"Published Version","isi":1,"status":"public","date_updated":"2025-04-14T07:43:59Z","department":[{"_id":"BjHo"}],"article_processing_charge":"No","author":[{"id":"2A2006B2-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0002-3072-5999","first_name":"Atul","last_name":"Varshney","full_name":"Varshney, Atul"},{"first_name":"Victor","full_name":"Steinberg, Victor","last_name":"Steinberg"}],"scopus_import":"1","file_date_updated":"2020-07-14T12:45:12Z","project":[{"name":"ISTplus - Postdoctoral Fellowships","_id":"260C2330-B435-11E9-9278-68D0E5697425","call_identifier":"H2020","grant_number":"754411"}],"citation":{"ama":"Varshney A, Steinberg V. Drag enhancement and drag reduction in viscoelastic flow. <i>Physical Review Fluids</i>. 2018;3(10). doi:<a href=\"https://doi.org/10.1103/PhysRevFluids.3.103302\">10.1103/PhysRevFluids.3.103302</a>","apa":"Varshney, A., &#38; Steinberg, V. (2018). Drag enhancement and drag reduction in viscoelastic flow. <i>Physical Review Fluids</i>. American Physical Society. <a href=\"https://doi.org/10.1103/PhysRevFluids.3.103302\">https://doi.org/10.1103/PhysRevFluids.3.103302</a>","chicago":"Varshney, Atul, and Victor Steinberg. “Drag Enhancement and Drag Reduction in Viscoelastic Flow.” <i>Physical Review Fluids</i>. American Physical Society, 2018. <a href=\"https://doi.org/10.1103/PhysRevFluids.3.103302\">https://doi.org/10.1103/PhysRevFluids.3.103302</a>.","ieee":"A. Varshney and V. Steinberg, “Drag enhancement and drag reduction in viscoelastic flow,” <i>Physical Review Fluids</i>, vol. 3, no. 10. American Physical Society, 2018.","ista":"Varshney A, Steinberg V. 2018. Drag enhancement and drag reduction in viscoelastic flow. Physical Review Fluids. 3(10), 103302.","short":"A. Varshney, V. Steinberg, Physical Review Fluids 3 (2018).","mla":"Varshney, Atul, and Victor Steinberg. “Drag Enhancement and Drag Reduction in Viscoelastic Flow.” <i>Physical Review Fluids</i>, vol. 3, no. 10, 103302, American Physical Society, 2018, doi:<a href=\"https://doi.org/10.1103/PhysRevFluids.3.103302\">10.1103/PhysRevFluids.3.103302</a>."},"has_accepted_license":"1","article_number":"103302 ","language":[{"iso":"eng"}],"pubrep_id":"1061","file":[{"content_type":"application/pdf","creator":"system","access_level":"open_access","date_created":"2018-12-12T10:10:14Z","file_id":"4800","file_size":1409040,"relation":"main_file","checksum":"e1445be33e8165114e96246275600750","file_name":"IST-2018-1061-v1+1_PhysRevFluids.3.103302.pdf","date_updated":"2020-07-14T12:45:12Z"}],"external_id":{"isi":["000447311500001"]},"user_id":"c635000d-4b10-11ee-a964-aac5a93f6ac1","month":"10"},{"user_id":"c635000d-4b10-11ee-a964-aac5a93f6ac1","month":"04","external_id":{"isi":["000425547700061"]},"acknowledgement":"S.Altmeyer is a Serra Húnter Fellow","file":[{"date_updated":"2020-07-14T12:46:37Z","file_name":"2018_Magnetism_Altmeyer.pdf","relation":"main_file","checksum":"431f5cd4a628d7ca21161f82b14ccb4f","file_size":17309535,"file_id":"7838","access_level":"open_access","date_created":"2020-05-14T14:41:17Z","creator":"dernst","content_type":"application/pdf"}],"page":"427 - 441","has_accepted_license":"1","citation":{"mla":"Altmeyer, Sebastian. “Non-Linear Dynamics and Alternating ‘Flip’ Solutions in Ferrofluidic Taylor-Couette Flow.” <i>Journal of Magnetism and Magnetic Materials</i>, vol. 452, Elsevier, 2018, pp. 427–41, doi:<a href=\"https://doi.org/10.1016/j.jmmm.2017.12.073\">10.1016/j.jmmm.2017.12.073</a>.","ista":"Altmeyer S. 2018. Non-linear dynamics and alternating ‘flip’ solutions in ferrofluidic Taylor-Couette flow. Journal of Magnetism and Magnetic Materials. 452, 427–441.","ieee":"S. Altmeyer, “Non-linear dynamics and alternating ‘flip’ solutions in ferrofluidic Taylor-Couette flow,” <i>Journal of Magnetism and Magnetic Materials</i>, vol. 452. Elsevier, pp. 427–441, 2018.","short":"S. Altmeyer, Journal of Magnetism and Magnetic Materials 452 (2018) 427–441.","ama":"Altmeyer S. Non-linear dynamics and alternating ‘flip’ solutions in ferrofluidic Taylor-Couette flow. <i>Journal of Magnetism and Magnetic Materials</i>. 2018;452:427-441. doi:<a href=\"https://doi.org/10.1016/j.jmmm.2017.12.073\">10.1016/j.jmmm.2017.12.073</a>","chicago":"Altmeyer, Sebastian. “Non-Linear Dynamics and Alternating ‘Flip’ Solutions in Ferrofluidic Taylor-Couette Flow.” <i>Journal of Magnetism and Magnetic Materials</i>. Elsevier, 2018. <a href=\"https://doi.org/10.1016/j.jmmm.2017.12.073\">https://doi.org/10.1016/j.jmmm.2017.12.073</a>.","apa":"Altmeyer, S. (2018). Non-linear dynamics and alternating ‘flip’ solutions in ferrofluidic Taylor-Couette flow. <i>Journal of Magnetism and Magnetic Materials</i>. Elsevier. <a href=\"https://doi.org/10.1016/j.jmmm.2017.12.073\">https://doi.org/10.1016/j.jmmm.2017.12.073</a>"},"language":[{"iso":"eng"}],"scopus_import":"1","file_date_updated":"2020-07-14T12:46:37Z","corr_author":"1","article_processing_charge":"No","author":[{"full_name":"Altmeyer, Sebastian","last_name":"Altmeyer","first_name":"Sebastian","id":"2EE67FDC-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0001-5964-0203"}],"date_updated":"2024-10-09T20:58:32Z","department":[{"_id":"BjHo"}],"isi":1,"status":"public","doi":"10.1016/j.jmmm.2017.12.073","publication_status":"published","oa_version":"Submitted Version","type":"journal_article","publist_id":"7297","volume":452,"article_type":"original","title":"Non-linear dynamics and alternating ‘flip’ solutions in ferrofluidic Taylor-Couette flow","publication":"Journal of Magnetism and Magnetic Materials","ddc":["530"],"_id":"519","day":"15","publisher":"Elsevier","oa":1,"date_published":"2018-04-15T00:00:00Z","year":"2018","intvolume":"       452","date_created":"2018-12-11T11:46:56Z","abstract":[{"text":"This study treats with the influence of a symmetry-breaking transversal magnetic field on the nonlinear dynamics of ferrofluidic Taylor-Couette flow – flow confined between two concentric independently rotating cylinders. We detected alternating ‘flip’ solutions which are flow states featuring typical characteristics of slow-fast-dynamics in dynamical systems. The flip corresponds to a temporal change in the axial wavenumber and we find them to appear either as pure 2-fold axisymmetric (due to the symmetry-breaking nature of the applied transversal magnetic field) or involving non-axisymmetric, helical modes in its interim solution. The latter ones show features of typical ribbon solutions. In any case the flip solutions have a preferential first axial wavenumber which corresponds to the more stable state (slow dynamics) and second axial wavenumber, corresponding to the short appearing more unstable state (fast dynamics). However, in both cases the flip time grows exponential with increasing the magnetic field strength before the flip solutions, living on 2-tori invariant manifolds, cease to exist, with lifetime going to infinity. Further we show that ferrofluidic flow turbulence differ from the classical, ordinary (usually at high Reynolds number) turbulence. The applied magnetic field hinders the free motion of ferrofluid partials and therefore smoothen typical turbulent quantities and features so that speaking of mildly chaotic dynamics seems to be a more appropriate expression for the observed motion. ","lang":"eng"}],"quality_controlled":"1"},{"day":"25","publisher":"Cambridge University Press","arxiv":1,"_id":"5996","title":"The critical point of the transition to turbulence in pipe flow","article_type":"original","ec_funded":1,"volume":839,"publication":"Journal of Fluid Mechanics","quality_controlled":"1","main_file_link":[{"url":"https://arxiv.org/abs/1709.06372","open_access":"1"}],"date_created":"2019-02-14T12:50:50Z","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"}],"intvolume":"       839","oa":1,"year":"2018","date_published":"2018-03-25T00:00:00Z","language":[{"iso":"eng"}],"citation":{"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>.","short":"M. Vasudevan, B. Hof, Journal of Fluid Mechanics 839 (2018) 76–94.","ista":"Vasudevan M, Hof B. 2018. The critical point of the transition to turbulence in pipe flow. Journal of Fluid Mechanics. 839, 76–94.","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.","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>","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>"},"project":[{"grant_number":"306589","name":"Decoding the complexity of turbulence at its origin","_id":"25152F3A-B435-11E9-9278-68D0E5697425","call_identifier":"FP7"}],"scopus_import":"1","month":"03","user_id":"c635000d-4b10-11ee-a964-aac5a93f6ac1","publication_identifier":{"eissn":["1469-7645"],"issn":["0022-1120"]},"external_id":{"isi":["000437858300003"],"arxiv":["1709.06372"]},"page":"76-94","acknowledgement":" We  also  thank  Philipp  Maier  and  the  IST  Austria  workshop  for  theirdedicated technical support","status":"public","isi":1,"oa_version":"Preprint","type":"journal_article","doi":"10.1017/jfm.2017.923","publication_status":"published","author":[{"last_name":"Vasudevan","full_name":"Vasudevan, Mukund","first_name":"Mukund","id":"3C5A959A-F248-11E8-B48F-1D18A9856A87"},{"first_name":"Björn","orcid":"0000-0003-2057-2754","id":"3A374330-F248-11E8-B48F-1D18A9856A87","full_name":"Hof, Björn","last_name":"Hof"}],"article_processing_charge":"No","department":[{"_id":"BjHo"}],"date_updated":"2025-04-14T13:36:56Z"},{"isi":1,"status":"public","doi":"10.1007/s10494-018-9896-4","publication_status":"published","oa_version":"Published Version","type":"journal_article","author":[{"first_name":"Jakob","orcid":"0000-0003-4312-0179","id":"3A47AE32-F248-11E8-B48F-1D18A9856A87","full_name":"Kühnen, Jakob","last_name":"Kühnen"},{"orcid":"0000-0001-5227-4271","id":"40315C30-F248-11E8-B48F-1D18A9856A87","first_name":"Davide","full_name":"Scarselli, Davide","last_name":"Scarselli"},{"full_name":"Schaner, Markus","last_name":"Schaner","first_name":"Markus","id":"316CE034-F248-11E8-B48F-1D18A9856A87"},{"full_name":"Hof, Björn","last_name":"Hof","first_name":"Björn","id":"3A374330-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0003-2057-2754"}],"article_processing_charge":"Yes (via OA deal)","date_updated":"2026-05-13T22:30:52Z","department":[{"_id":"BjHo"}],"has_accepted_license":"1","citation":{"apa":"Kühnen, J., Scarselli, D., Schaner, M., &#38; Hof, B. (2018). Relaminarization by steady modification of the streamwise velocity profile in a pipe. <i>Flow Turbulence and Combustion</i>. Springer. <a href=\"https://doi.org/10.1007/s10494-018-9896-4\">https://doi.org/10.1007/s10494-018-9896-4</a>","chicago":"Kühnen, Jakob, Davide Scarselli, Markus Schaner, and Björn Hof. “Relaminarization by Steady Modification of the Streamwise Velocity Profile in a Pipe.” <i>Flow Turbulence and Combustion</i>. Springer, 2018. <a href=\"https://doi.org/10.1007/s10494-018-9896-4\">https://doi.org/10.1007/s10494-018-9896-4</a>.","ama":"Kühnen J, Scarselli D, Schaner M, Hof B. Relaminarization by steady modification of the streamwise velocity profile in a pipe. <i>Flow Turbulence and Combustion</i>. 2018;100(4):919-942. doi:<a href=\"https://doi.org/10.1007/s10494-018-9896-4\">10.1007/s10494-018-9896-4</a>","ista":"Kühnen J, Scarselli D, Schaner M, Hof B. 2018. Relaminarization by steady modification of the streamwise velocity profile in a pipe. Flow Turbulence and Combustion. 100(4), 919–942.","ieee":"J. Kühnen, D. Scarselli, M. Schaner, and B. Hof, “Relaminarization by steady modification of the streamwise velocity profile in a pipe,” <i>Flow Turbulence and Combustion</i>, vol. 100, no. 4. Springer, pp. 919–942, 2018.","short":"J. Kühnen, D. Scarselli, M. Schaner, B. Hof, Flow Turbulence and Combustion 100 (2018) 919–942.","mla":"Kühnen, Jakob, et al. “Relaminarization by Steady Modification of the Streamwise Velocity Profile in a Pipe.” <i>Flow Turbulence and Combustion</i>, vol. 100, no. 4, Springer, 2018, pp. 919–42, doi:<a href=\"https://doi.org/10.1007/s10494-018-9896-4\">10.1007/s10494-018-9896-4</a>."},"language":[{"iso":"eng"}],"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"}],"file_date_updated":"2020-07-14T12:46:25Z","corr_author":"1","user_id":"c635000d-4b10-11ee-a964-aac5a93f6ac1","month":"01","external_id":{"isi":["000433113900004"]},"file":[{"file_size":2210020,"checksum":"d7c0bade150faabca150b0a9986e60ca","relation":"main_file","date_updated":"2020-07-14T12:46:25Z","file_name":"2018_FlowTurbulenceCombust_Kuehnen.pdf","content_type":"application/pdf","creator":"dernst","date_created":"2018-12-17T15:52:37Z","access_level":"open_access","file_id":"5717"}],"related_material":{"record":[{"relation":"dissertation_contains","status":"public","id":"7258"}]},"page":"919 - 942","date_created":"2018-12-11T11:46:23Z","intvolume":"       100","abstract":[{"text":"We show that a rather simple, steady modification of the streamwise velocity profile in a pipe can lead to a complete collapse of turbulence and the flow fully relaminarizes. Two different devices, a stationary obstacle (inset) and a device which injects fluid through an annular gap close to the wall, are used to control the flow. Both devices modify the streamwise velocity profile such that the flow in the center of the pipe is decelerated and the flow in the near wall region is accelerated. We present measurements with stereoscopic particle image velocimetry to investigate and capture the development of the relaminarizing flow downstream these devices and the specific circumstances responsible for relaminarization. We find total relaminarization up to Reynolds numbers of 6000, where the skin friction in the far downstream distance is reduced by a factor of 3.4 due to relaminarization. In a smooth straight pipe the flow remains completely laminar downstream of the control. Furthermore, we show that transient (temporary) relaminarization in a spatially confined region right downstream the devices occurs also at much higher Reynolds numbers, accompanied by a significant local skin friction drag reduction. The underlying physical mechanism of relaminarization is attributed to a weakening of the near-wall turbulence production cycle.","lang":"eng"}],"quality_controlled":"1","tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","image":"/images/cc_by.png","short":"CC BY (4.0)"},"oa":1,"date_published":"2018-01-01T00:00:00Z","issue":"4","year":"2018","ddc":["530"],"_id":"422","day":"01","publisher":"Springer","volume":100,"publist_id":"7401","title":"Relaminarization by steady modification of the streamwise velocity profile in a pipe","ec_funded":1,"publication":"Flow Turbulence and Combustion"},{"status":"public","isi":1,"oa_version":"Preprint","type":"journal_article","doi":"10.1038/s41567-017-0018-3","publication_status":"published","author":[{"last_name":"Kühnen","full_name":"Kühnen, Jakob","first_name":"Jakob","id":"3A47AE32-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0003-4312-0179"},{"first_name":"Baofang","last_name":"Song","full_name":"Song, Baofang"},{"full_name":"Scarselli, Davide","last_name":"Scarselli","id":"40315C30-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0001-5227-4271","first_name":"Davide"},{"full_name":"Budanur, Nazmi B","last_name":"Budanur","id":"3EA1010E-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0003-0423-5010","first_name":"Nazmi B"},{"orcid":"0000-0003-4844-6311","id":"3BE60946-F248-11E8-B48F-1D18A9856A87","first_name":"Michael","full_name":"Riedl, Michael","last_name":"Riedl"},{"last_name":"Willis","full_name":"Willis, Ashley","first_name":"Ashley"},{"last_name":"Avila","full_name":"Avila, Marc","first_name":"Marc"},{"last_name":"Hof","full_name":"Hof, Björn","first_name":"Björn","id":"3A374330-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0003-2057-2754"}],"article_processing_charge":"No","department":[{"_id":"BjHo"}],"date_updated":"2026-05-13T22:30:52Z","language":[{"iso":"eng"}],"citation":{"ieee":"J. Kühnen <i>et al.</i>, “Destabilizing turbulence in pipe flow,” <i>Nature Physics</i>, vol. 14. Nature Publishing Group, pp. 386–390, 2018.","short":"J. Kühnen, B. Song, D. Scarselli, N.B. Budanur, M. Riedl, A. Willis, M. Avila, B. Hof, Nature Physics 14 (2018) 386–390.","ista":"Kühnen J, Song B, Scarselli D, Budanur NB, Riedl M, Willis A, Avila M, Hof B. 2018. Destabilizing turbulence in pipe flow. Nature Physics. 14, 386–390.","mla":"Kühnen, Jakob, et al. “Destabilizing Turbulence in Pipe Flow.” <i>Nature Physics</i>, vol. 14, Nature Publishing Group, 2018, pp. 386–90, doi:<a href=\"https://doi.org/10.1038/s41567-017-0018-3\">10.1038/s41567-017-0018-3</a>.","ama":"Kühnen J, Song B, Scarselli D, et al. Destabilizing turbulence in pipe flow. <i>Nature Physics</i>. 2018;14:386-390. doi:<a href=\"https://doi.org/10.1038/s41567-017-0018-3\">10.1038/s41567-017-0018-3</a>","apa":"Kühnen, J., Song, B., Scarselli, D., Budanur, N. B., Riedl, M., Willis, A., … Hof, B. (2018). Destabilizing turbulence in pipe flow. <i>Nature Physics</i>. Nature Publishing Group. <a href=\"https://doi.org/10.1038/s41567-017-0018-3\">https://doi.org/10.1038/s41567-017-0018-3</a>","chicago":"Kühnen, Jakob, Baofang Song, Davide Scarselli, Nazmi B Budanur, Michael Riedl, Ashley Willis, Marc Avila, and Björn Hof. “Destabilizing Turbulence in Pipe Flow.” <i>Nature Physics</i>. Nature Publishing Group, 2018. <a href=\"https://doi.org/10.1038/s41567-017-0018-3\">https://doi.org/10.1038/s41567-017-0018-3</a>."},"project":[{"grant_number":"306589","_id":"25152F3A-B435-11E9-9278-68D0E5697425","name":"Decoding the complexity of turbulence at its origin","call_identifier":"FP7"},{"grant_number":"737549","_id":"25104D44-B435-11E9-9278-68D0E5697425","name":"Eliminating turbulence in oil pipelines","call_identifier":"H2020"}],"corr_author":"1","scopus_import":"1","month":"01","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","external_id":{"isi":["000429434100020"],"arxiv":["1711.06543"]},"page":"386-390","related_material":{"record":[{"relation":"dissertation_contains","status":"public","id":"12726"},{"status":"public","relation":"dissertation_contains","id":"14530"},{"id":"7258","status":"public","relation":"dissertation_contains"}]},"acknowledgement":"We acknowledge the European Research Council under the European Union’s Seventh Framework Programme (FP/2007-2013)/ERC Grant Agreement 306589, the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement no. 737549) and the Deutsche Forschungsgemeinschaft (Project No. FOR 1182) for financial support. We thank our technician P. Maier for providing highly valuable ideas and greatly supporting us in all technical aspects. We thank M. Schaner for technical drawings, construction and design. We thank M. Schwegel for a Matlab code to post-process experimental data.","quality_controlled":"1","main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/1711.06543"}],"intvolume":"        14","abstract":[{"lang":"eng","text":"Turbulence is the major cause of friction losses in transport processes and it is responsible for a drastic drag increase in flows over bounding surfaces. While much effort is invested into developing ways to control and reduce turbulence intensities, so far no methods exist to altogether eliminate turbulence if velocities are sufficiently large. We demonstrate for pipe flow that appropriate distortions to the velocity profile lead to a complete collapse of turbulence and subsequently friction losses are reduced by as much as 90%. Counterintuitively, the return to laminar motion is accomplished by initially increasing turbulence intensities or by transiently amplifying wall shear. Since neither the Reynolds number nor the shear stresses decrease (the latter often increase), these measures are not indicative of turbulence collapse. Instead, an amplification mechanism                      measuring the interaction between eddies and the mean shear is found to set a threshold below which turbulence is suppressed beyond recovery."}],"date_created":"2018-12-11T11:46:36Z","oa":1,"year":"2018","date_published":"2018-01-08T00:00:00Z","day":"08","arxiv":1,"publisher":"Nature Publishing Group","_id":"461","title":"Destabilizing turbulence in pipe flow","ec_funded":1,"publist_id":"7360","volume":14,"publication":"Nature Physics"},{"year":"2017","date_published":"2017-01-06T00:00:00Z","oa":1,"tmp":{"legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode","name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","image":"/images/cc_by.png","short":"CC BY (4.0)"},"quality_controlled":"1","date_created":"2018-12-11T11:50:28Z","intvolume":"         7","abstract":[{"lang":"eng","text":"We investigate fundamental nonlinear dynamics of ferrofluidic Taylor-Couette flow - flow confined be-tween two concentric independently rotating cylinders - consider small aspect ratio by solving the ferro-hydrodynamical equations, carrying out systematic bifurcation analysis. Without magnetic field, we find steady flow patterns, previously observed with a simple fluid, such as those containing normal one- or two vortex cells, as well as anomalous one-cell and twin-cell flow states. However, when a symmetry-breaking transverse magnetic field is present, all flow states exhibit stimulated, finite two-fold mode. Various bifurcations between steady and unsteady states can occur, corresponding to the transitions between the two-cell and one-cell states. While unsteady, axially oscillating flow states can arise, we also detect the emergence of new unsteady flow states. In particular, we uncover two new states: one contains only the azimuthally oscillating solution in the configuration of the twin-cell flow state, and an-other a rotating flow state. Topologically, these flow states are a limit cycle and a quasiperiodic solution on a two-torus, respectively. Emergence of new flow states in addition to observed ones with classical fluid, indicates that richer but potentially more controllable dynamics in ferrofluidic flows, as such flow states depend on the external magnetic field."}],"publication":"Scientific Reports","title":"Dynamics of ferrofluidic flow in the Taylor-Couette system with a small aspect ratio","publist_id":"6198","volume":7,"publisher":"Nature Publishing Group","day":"06","_id":"1160","ddc":["532"],"department":[{"_id":"BjHo"}],"date_updated":"2025-07-10T11:50:13Z","author":[{"last_name":"Altmeyer","full_name":"Altmeyer, Sebastian","orcid":"0000-0001-5964-0203","id":"2EE67FDC-F248-11E8-B48F-1D18A9856A87","first_name":"Sebastian"},{"first_name":"Younghae","full_name":"Do, Younghae","last_name":"Do"},{"last_name":"Lai","full_name":"Lai, Ying","first_name":"Ying"}],"article_processing_charge":"No","type":"journal_article","oa_version":"Published Version","publication_status":"published","doi":"10.1038/srep40012","status":"public","isi":1,"publication_identifier":{"issn":["2045-2322"]},"file":[{"creator":"system","content_type":"application/pdf","file_id":"4802","access_level":"open_access","date_created":"2018-12-12T10:10:16Z","relation":"main_file","checksum":"694aa70399444570825099c1a7ec91f2","file_size":4546835,"date_updated":"2020-07-14T12:44:36Z","file_name":"IST-2017-743-v1+1_srep40012.pdf"}],"external_id":{"isi":["000391269700001"]},"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","month":"01","file_date_updated":"2020-07-14T12:44:36Z","scopus_import":"1","language":[{"iso":"eng"}],"pubrep_id":"743","citation":{"mla":"Altmeyer, Sebastian, et al. “Dynamics of Ferrofluidic Flow in the Taylor-Couette System with a Small Aspect Ratio.” <i>Scientific Reports</i>, vol. 7, 40012, Nature Publishing Group, 2017, doi:<a href=\"https://doi.org/10.1038/srep40012\">10.1038/srep40012</a>.","ieee":"S. Altmeyer, Y. Do, and Y. Lai, “Dynamics of ferrofluidic flow in the Taylor-Couette system with a small aspect ratio,” <i>Scientific Reports</i>, vol. 7. Nature Publishing Group, 2017.","short":"S. Altmeyer, Y. Do, Y. Lai, Scientific Reports 7 (2017).","ista":"Altmeyer S, Do Y, Lai Y. 2017. Dynamics of ferrofluidic flow in the Taylor-Couette system with a small aspect ratio. Scientific Reports. 7, 40012.","ama":"Altmeyer S, Do Y, Lai Y. Dynamics of ferrofluidic flow in the Taylor-Couette system with a small aspect ratio. <i>Scientific Reports</i>. 2017;7. doi:<a href=\"https://doi.org/10.1038/srep40012\">10.1038/srep40012</a>","chicago":"Altmeyer, Sebastian, Younghae Do, and Ying Lai. “Dynamics of Ferrofluidic Flow in the Taylor-Couette System with a Small Aspect Ratio.” <i>Scientific Reports</i>. Nature Publishing Group, 2017. <a href=\"https://doi.org/10.1038/srep40012\">https://doi.org/10.1038/srep40012</a>.","apa":"Altmeyer, S., Do, Y., &#38; Lai, Y. (2017). Dynamics of ferrofluidic flow in the Taylor-Couette system with a small aspect ratio. <i>Scientific Reports</i>. Nature Publishing Group. <a href=\"https://doi.org/10.1038/srep40012\">https://doi.org/10.1038/srep40012</a>"},"has_accepted_license":"1","article_number":"40012"},{"scopus_import":"1","file_date_updated":"2020-07-14T12:44:39Z","has_accepted_license":"1","citation":{"mla":"Budanur, Nazmi B., and Predrag Cvitanović. “Unstable Manifolds of Relative Periodic Orbits in the Symmetry Reduced State Space of the Kuramoto–Sivashinsky System.” <i>Journal of Statistical Physics</i>, vol. 167, no. 3–4, Springer, 2017, pp. 636–55, doi:<a href=\"https://doi.org/10.1007/s10955-016-1672-z\">10.1007/s10955-016-1672-z</a>.","short":"N.B. Budanur, P. Cvitanović, Journal of Statistical Physics 167 (2017) 636–655.","ista":"Budanur NB, Cvitanović P. 2017. Unstable manifolds of relative periodic orbits in the symmetry reduced state space of the Kuramoto–Sivashinsky system. Journal of Statistical Physics. 167(3–4), 636–655.","ieee":"N. B. Budanur and P. Cvitanović, “Unstable manifolds of relative periodic orbits in the symmetry reduced state space of the Kuramoto–Sivashinsky system,” <i>Journal of Statistical Physics</i>, vol. 167, no. 3–4. Springer, pp. 636–655, 2017.","ama":"Budanur NB, Cvitanović P. Unstable manifolds of relative periodic orbits in the symmetry reduced state space of the Kuramoto–Sivashinsky system. <i>Journal of Statistical Physics</i>. 2017;167(3-4):636-655. doi:<a href=\"https://doi.org/10.1007/s10955-016-1672-z\">10.1007/s10955-016-1672-z</a>","chicago":"Budanur, Nazmi B, and Predrag Cvitanović. “Unstable Manifolds of Relative Periodic Orbits in the Symmetry Reduced State Space of the Kuramoto–Sivashinsky System.” <i>Journal of Statistical Physics</i>. Springer, 2017. <a href=\"https://doi.org/10.1007/s10955-016-1672-z\">https://doi.org/10.1007/s10955-016-1672-z</a>.","apa":"Budanur, N. B., &#38; Cvitanović, P. (2017). Unstable manifolds of relative periodic orbits in the symmetry reduced state space of the Kuramoto–Sivashinsky system. <i>Journal of Statistical Physics</i>. Springer. <a href=\"https://doi.org/10.1007/s10955-016-1672-z\">https://doi.org/10.1007/s10955-016-1672-z</a>"},"pubrep_id":"782","language":[{"iso":"eng"}],"external_id":{"isi":["000400233600014"]},"acknowledgement":"This work was supported by the family of late G. Robinson, Jr. and NSF Grant DMS-1211827. ","page":"636-655","file":[{"creator":"system","content_type":"application/pdf","file_id":"5319","date_created":"2018-12-12T10:18:01Z","access_level":"open_access","checksum":"3e971d09eb167761aa0888ed415b0056","relation":"main_file","file_size":2820207,"file_name":"IST-2017-782-v1+1_BudCvi15.pdf","date_updated":"2020-07-14T12:44:39Z"}],"month":"05","user_id":"317138e5-6ab7-11ef-aa6d-ffef3953e345","doi":"10.1007/s10955-016-1672-z","publication_status":"published","oa_version":"Submitted Version","type":"journal_article","isi":1,"status":"public","date_updated":"2025-09-22T09:36:50Z","department":[{"_id":"BjHo"}],"article_processing_charge":"No","author":[{"id":"3EA1010E-F248-11E8-B48F-1D18A9856A87","orcid":"0000-0003-0423-5010","first_name":"Nazmi B","last_name":"Budanur","full_name":"Budanur, Nazmi B"},{"first_name":"Predrag","last_name":"Cvitanović","full_name":"Cvitanović, Predrag"}],"_id":"1211","day":"01","publisher":"Springer","ddc":["530"],"publication":"Journal of Statistical Physics","volume":167,"publist_id":"6136","title":"Unstable manifolds of relative periodic orbits in the symmetry reduced state space of the Kuramoto–Sivashinsky system","date_created":"2018-12-11T11:50:44Z","intvolume":"       167","abstract":[{"lang":"eng","text":"Systems such as fluid flows in channels and pipes or the complex Ginzburg–Landau system, defined over periodic domains, exhibit both continuous symmetries, translational and rotational, as well as discrete symmetries under spatial reflections or complex conjugation. The simplest, and very common symmetry of this type is the equivariance of the defining equations under the orthogonal group O(2). We formulate a novel symmetry reduction scheme for such systems by combining the method of slices with invariant polynomial methods, and show how it works by applying it to the Kuramoto–Sivashinsky system in one spatial dimension. As an example, we track a relative periodic orbit through a sequence of bifurcations to the onset of chaos. Within the symmetry-reduced state space we are able to compute and visualize the unstable manifolds of relative periodic orbits, their torus bifurcations, a transition to chaos via torus breakdown, and heteroclinic connections between various relative periodic orbits. It would be very hard to carry through such analysis in the full state space, without a symmetry reduction such as the one we present here."}],"quality_controlled":"1","date_published":"2017-05-01T00:00:00Z","issue":"3-4","year":"2017","oa":1},{"publication":"Journal of Fluid Mechanics","publist_id":"6290","volume":813,"title":"Speed and structure of turbulent fronts in pipe flow","ec_funded":1,"_id":"1087","day":"25","arxiv":1,"publisher":"Cambridge University Press","date_published":"2017-02-25T00:00:00Z","year":"2017","oa":1,"main_file_link":[{"open_access":"1","url":"https://arxiv.org/abs/1603.04077"}],"abstract":[{"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.","lang":"eng"}],"date_created":"2018-12-11T11:50:04Z","intvolume":"       813","quality_controlled":"1","acknowledged_ssus":[{"_id":"ScienComp"}],"external_id":{"isi":["000394376400044"],"arxiv":["1603.04077"]},"page":"1045 - 1059","publication_identifier":{"issn":["0022-1120"]},"month":"02","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","scopus_import":"1","project":[{"grant_number":"306589","name":"Decoding the complexity of turbulence at its origin","_id":"25152F3A-B435-11E9-9278-68D0E5697425","call_identifier":"FP7"}],"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.","short":"B. Song, D. Barkley, B. Hof, M. Avila, Journal of Fluid Mechanics 813 (2017) 1045–1059.","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>.","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>","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>","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>."},"language":[{"iso":"eng"}],"date_updated":"2025-06-04T08:35:11Z","department":[{"_id":"BjHo"}],"article_processing_charge":"No","author":[{"last_name":"Song","full_name":"Song, Baofang","first_name":"Baofang"},{"first_name":"Dwight","full_name":"Barkley, Dwight","last_name":"Barkley"},{"last_name":"Hof","full_name":"Hof, Björn","orcid":"0000-0003-2057-2754","id":"3A374330-F248-11E8-B48F-1D18A9856A87","first_name":"Björn"},{"full_name":"Avila, Marc","last_name":"Avila","first_name":"Marc"}],"doi":"10.1017/jfm.2017.14","publication_status":"published","oa_version":"Submitted Version","type":"journal_article","isi":1,"status":"public"}]