Direct numerical simulation of stochastically forced laminar plane couette flow: peculiarities of hydrodynamic fluctuations.
The background of three-dimensional hydrodynamic (vortical) fluctuations in a stochastically forced, laminar, incompressible, plane Couette flow is simulated numerically. The fluctuating field is anisotropic and has well pronounced peculiarities: (i) the hydrodynamic fluctuations exhibit nonexponential, transient growth; (ii) fluctuations with the streamwise characteristic length scale about 2 times larger than the channel width are predominant in the fluctuating spectrum instead of streamwise constant ones; (iii) nonzero cross correlations of velocity (even streamwise-spanwise) components appear; (iv) stochastic forcing destroys the spanwise reflection symmetry (inherent to the linear and full Navier-Stokes equations in a case of the Couette flow) and causes an asymmetry of the dynamical processes.
Khujadze
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G
Department of Mechanical Engineering, Group of Fluid Dynamics, Petersenstr. 13, Darmstadt, Germany.
Oberlack
M
M
Chagelishvili
G
G