Zobrazeno 1 - 10
of 19
pro vyhledávání: '"M. J. Philipp Hack"'
Publikováno v:
IUTAM Laminar-Turbulent Transition ISBN: 9783030679019
We present a variational method for the computation and analysis of nonlinear optimal perturbations in compressible flows. The method is verified in parallel periodic pipe flow at \(Re = 1750\) and \(Ma = 0.20\). At low initial perturbation energy, t
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::49f6cfb81673bd83aebefd4d90856cea
https://doi.org/10.1007/978-3-030-67902-6_6
https://doi.org/10.1007/978-3-030-67902-6_6
Autor:
Michael Karp, M. J. Philipp Hack
Publikováno v:
IUTAM Laminar-Turbulent Transition ISBN: 9783030679019
IUTAM Laminar-Turbulent Transition
IUTAM Laminar-Turbulent Transition
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::7f782499513527bd7463c2858cb3e299
https://doi.org/10.1007/978-3-030-67902-6_37
https://doi.org/10.1007/978-3-030-67902-6_37
Publikováno v:
Journal of Fluid Mechanics. 911
A novel mechanism for the amplification of distortions to the material interface of liquid jets is identified. The mechanism is independent of the exponential instability of the flow and can intensify small perturbations to the material interface by
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::2f277a53a2fbde15305a99e8bd38962a
https://doi.org/10.1017/jfm.2020.1067
https://doi.org/10.1017/jfm.2020.1067
Autor:
M. J. Philipp Hack, Oliver T. Schmidt
Publikováno v:
Journal of Fluid Mechanics. 907
The mechanics of extreme intensity events in the buffer and logarithmic layers of a turbulent channel at is investigated. The 99.9th percentile of the most intense events in the dissipation of turbulent kinetic energy is analysed by means of conditio
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::03d0b2d138bf9084c0f8a4bfcc0a93e4
https://doi.org/10.1017/jfm.2020.798
https://doi.org/10.1017/jfm.2020.798
Autor:
Zhu Huang, M. J. Philipp Hack
Publikováno v:
Journal of Fluid Mechanics. 894
A variational framework for the identification and analysis of general nonlinear optimal disturbances in compressible flows is derived. The formulation is based on the compressible Navier–Stokes equations in conserved variables for an ideal gas wit
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::1c93866ef41c461469efa8a35e447cc9
https://doi.org/10.1017/jfm.2020.189
https://doi.org/10.1017/jfm.2020.189
Autor:
Michael Karp, M. J. Philipp Hack
Publikováno v:
Journal of Fluid Mechanics. 892
By means of nonlinear optimization, we seek the velocity disturbances at a given upstream position that suppress a laminar separation bubble as effectively as possible. Both steady and unsteady disturbances are examined and compared. For steady distu
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::0040cb21bcb407c317537f0450436cc8
https://doi.org/10.1017/jfm.2020.157
https://doi.org/10.1017/jfm.2020.157
Autor:
Michael Karp, M. J. Philipp Hack
Publikováno v:
Journal of Fluid Mechanics. 855:1208-1237
Although boundary-layer flows over convex surfaces are exponentially stable, non-modal mechanisms may enable significant disturbance growth which can make the flow susceptible to secondary instabilities. A parametric investigation of the transient gr
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::1400f539c39c0868ed2ef1abc2cd1c58
https://doi.org/10.1017/jfm.2018.690
https://doi.org/10.1017/jfm.2018.690
Autor:
M. J. Philipp Hack, Parviz Moin
Publikováno v:
Journal of Fluid Mechanics. 844:917-955
The mechanism underlying the coherent hairpin process in wall-bounded shear flows is studied. An algorithm for the identification and analysis of flow structures based on morphological operations is presented. The method distils the topology of the f
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::fa579ab564066e39418a0bc7da75725a
https://doi.org/10.1017/jfm.2018.202
https://doi.org/10.1017/jfm.2018.202
Autor:
M. J. Philipp Hack, Parviz Moin
Publikováno v:
Journal of Fluid Mechanics. 829:112-126
Algebraic disturbance growth in spatially developing boundary-layer flows is investigated using an optimization approach. The methodology builds on the framework of the parabolized stability equations and avoids some of the limitations associated wit
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::f6e056e00f93e56f7ce6ff7aa8b3d465
https://doi.org/10.1017/jfm.2017.557
https://doi.org/10.1017/jfm.2017.557
Publikováno v:
ACC
We utilize control-theoretic tools to study the receptivity of pre-transitional boundary layers to persistent stochastic excitation sources. White-in-time stochastic excitation is used to model the effect of free-stream turbulence on the linearized N
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::e7b730eedc6d58f96157f576016a74b1
https://doi.org/10.23919/acc.2019.8814591
https://doi.org/10.23919/acc.2019.8814591