Imperial College London
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ProfessorSergeiChernyshenko

Faculty of Engineering, Department of Aeronautics

Chair in Aerodynamics
 
 
 
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Contact

 

+44 (0)20 7594 5548s.chernyshenko Website

 
 
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Location

 

211aCity and Guilds BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Jiao:2021:10.1103/PhysRevFluids.6.023902,
author = {Jiao, Y and Hwang, Y and Chernyshenko, S},
doi = {10.1103/PhysRevFluids.6.023902},
journal = {Physical Review Fluids},
title = {The Orr mechanism in transition of parallel shear flow},
url = {http://dx.doi.org/10.1103/PhysRevFluids.6.023902},
volume = {6},
year = {2021}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - The Orr mechanism is revisited to understand its precise role in the transition of plane Couette flow. By considering homogeneous shear flow and plane Couette flow, it is identified that the Orr mechanism induces a lift-up effect which significantly amplifies spanwise velocity. An optimal perturbation analysis for an individual velocity component reveals that the amplification of spanwise velocity is most active at the streamwise length comparable to the given spanwise length of the perturbation. The relevance of this mechanism to transition is subsequently examined in plane Couette flow. To this end, a set of initial conditions, which combines the optimal perturbation for spanwise velocity with the one for all the velocity components, is considered by varying their amplitudes. Two representative transition scenarios are found: oblique and streak transitions. In the former, the spanwise velocity perturbation amplified with the Orr mechanism initiates both streak amplification and breakdown, whereas in the latter, its role is limited only to the streak breakdown at the late stage of transition. As such, the oblique transition offers a route to turbulence energetically more efficient than the streak transition, at least for the cases examined in the present paper. Finally, the oblique transition is found to share many physical similarities with the transition by the minimal seed.
AU  - Jiao,Y
AU  - Hwang,Y
AU  - Chernyshenko,S
DO  - 10.1103/PhysRevFluids.6.023902
PY  - 2021///
SN  - 2469-990X
TI  - The Orr mechanism in transition of parallel shear flow
T2  - Physical Review Fluids
UR  - http://dx.doi.org/10.1103/PhysRevFluids.6.023902
UR  - http://hdl.handle.net/10044/1/86956
VL  - 6
ER  -
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