{"department":[{"_id":"HeEd"}],"acknowledgement":"The authors acknowledge funding of the German Re-\r\nsearch  Foundation  (DFG)  via  the  Collaborative  Re-\r\nsearch  Center  (SFB  557)  \\Control  of  Complex  Turbu-\r\nlent  Shear  Flows\"  and  the  Emmy  Noether  Program.\r\nFurther  funding  was  provided  by  the  Zuse  Institute\r\nBerlin  (ZIB),  the  DFG-CNRS  research  group  \\Noise\r\nGeneration in Turbulent Flows\" (2003{2010), the Chaire\r\nd'Excellence 'Closed-loop control of turbulent shear  ows\r\nusing reduced-order models' (TUCOROM) of the French\r\nAgence Nationale de la Recherche (ANR), and the Eu-\r\nropean  Social  Fund  (ESF  App.   No.   100098251).   We\r\nthank  the  Ambrosys  Ltd.  Society  for  Complex  Sys-\r\ntems  Management  and  the  Bernd  R.  Noack  Cybernet-\r\nics  Foundation  for  additional  support.   A  part  of  this\r\nwork was performed using HPC resources from GENCI-[CCRT/CINES/IDRIS]  supported  by  the  Grant  2011-\r\n[x2011020912","date_created":"2018-12-11T11:50:46Z","month":"01","citation":{"apa":"Kasten, J., Reininghaus, J., Hotz, I., Hege, H., Noack, B., Daviller, G., &#38; Morzyński, M. (2016). Acceleration feature points of unsteady shear flows. <i>Archives of Mechanics</i>. Polish Academy of Sciences Publishing House.","ista":"Kasten J, Reininghaus J, Hotz I, Hege H, Noack B, Daviller G, Morzyński M. 2016. Acceleration feature points of unsteady shear flows. Archives of Mechanics. 68(1), 55–80.","chicago":"Kasten, Jens, Jan Reininghaus, Ingrid Hotz, Hans Hege, Bernd Noack, Guillaume Daviller, and Marek Morzyński. “Acceleration Feature Points of Unsteady Shear Flows.” <i>Archives of Mechanics</i>. Polish Academy of Sciences Publishing House, 2016.","ieee":"J. Kasten <i>et al.</i>, “Acceleration feature points of unsteady shear flows,” <i>Archives of Mechanics</i>, vol. 68, no. 1. Polish Academy of Sciences Publishing House, pp. 55–80, 2016.","short":"J. Kasten, J. Reininghaus, I. Hotz, H. Hege, B. Noack, G. Daviller, M. Morzyński, Archives of Mechanics 68 (2016) 55–80.","mla":"Kasten, Jens, et al. “Acceleration Feature Points of Unsteady Shear Flows.” <i>Archives of Mechanics</i>, vol. 68, no. 1, Polish Academy of Sciences Publishing House, 2016, pp. 55–80.","ama":"Kasten J, Reininghaus J, Hotz I, et al. Acceleration feature points of unsteady shear flows. <i>Archives of Mechanics</i>. 2016;68(1):55-80."},"day":"01","page":"55 - 80","status":"public","year":"2016","publisher":"Polish Academy of Sciences Publishing House","oa":1,"user_id":"3E5EF7F0-F248-11E8-B48F-1D18A9856A87","date_published":"2016-01-01T00:00:00Z","type":"journal_article","volume":68,"publist_id":"6118","date_updated":"2021-01-12T06:49:09Z","language":[{"iso":"eng"}],"intvolume":"        68","title":"Acceleration feature points of unsteady shear flows","scopus_import":1,"quality_controlled":"1","author":[{"last_name":"Kasten","first_name":"Jens","full_name":"Kasten, Jens"},{"last_name":"Reininghaus","id":"4505473A-F248-11E8-B48F-1D18A9856A87","first_name":"Jan","full_name":"Reininghaus, Jan"},{"first_name":"Ingrid","full_name":"Hotz, Ingrid","last_name":"Hotz"},{"full_name":"Hege, Hans","first_name":"Hans","last_name":"Hege"},{"last_name":"Noack","first_name":"Bernd","full_name":"Noack, Bernd"},{"last_name":"Daviller","first_name":"Guillaume","full_name":"Daviller, Guillaume"},{"last_name":"Morzyński","full_name":"Morzyński, Marek","first_name":"Marek"}],"main_file_link":[{"open_access":"1","url":"http://am.ippt.pan.pl/am/article/viewFile/v68p55/pdf"}],"_id":"1216","abstract":[{"text":"A framework fo r extracting features in 2D transient flows, based on the acceleration field to ensure Galilean invariance is proposed in this paper. The minima of the acceleration magnitude (a superset of acceleration zeros) are extracted and discriminated into vortices and saddle points, based on the spectral properties of the velocity Jacobian. The extraction of topological features is performed with purely combinatorial algorithms from discrete computational topology. The feature points are prioritized with persistence, as a physically meaningful importance measure. These feature points are tracked in time with a robust algorithm for tracking features. Thus, a space-time hierarchy of the minima is built and vortex merging events are detected. We apply the acceleration feature extraction strategy to three two-dimensional shear flows: (1) an incompressible periodic cylinder wake, (2) an incompressible planar mixing layer and (3) a weakly compressible planar jet. The vortex-like acceleration feature points are shown to be well aligned with acceleration zeros, maxima of the vorticity magnitude, minima of the pressure field and minima of λ2.","lang":"eng"}],"oa_version":"Published Version","issue":"1","publication_status":"published","publication":"Archives of Mechanics"}