FULLY DEVELOPED STAGE OF PERTURBATIONS IN PARALLEL TRANSVERSE SHEAR FLOWS
نویسندگان
چکیده
منابع مشابه
A minimum action method for small random perturbations of two-dimensional parallel shear flows
In this work, we develop a parallel minimum action method for small random perturbations of Navier–Stokes equations to solve the optimization problem given by the large deviation theory. The Freidlin–Wentzell action functional is discretized by hp finite elements in time direction and spectral methods in physical space. A simple diagonal preconditioner is constructed for the nonlinear conjugate...
متن کاملSelf-sustaining vortex perturbations in smooth shear flows
The nonlinear dynamics of coherent circular/elliptical cyclonic and anticyclonic vortices in plane flow with constant shear is investigated numerically using a dealiased Fourier pseudospectral code. The flow is asymptotically linearly stable, but is highly non-normal, allowing perturbations to gain energy transiently from the background shear flow. This linear transient growth interplays with n...
متن کاملTransverse electron-scale instability in relativistic shear flows.
Electron-scale surface waves are shown to be unstable in the transverse plane of a sheared flow in an initially unmagnetized collisionless plasma, not captured by (magneto)hydrodynamics. It is found that these unstable modes have a higher growth rate than the closely related electron-scale Kelvin-Helmholtz instability in relativistic shears. Multidimensional particle-in-cell simulations verify ...
متن کاملOn the role of vortex stretching in energy optimal growth of three-dimensional perturbations on plane parallel shear flows
The three-dimensional linearized optimal energy growth mechanism, in plane parallel shear flows, is re-examined in terms of the role of vortex stretching and the interplay between the spanwise vorticity and the planar divergent components. For high Reynolds numbers the structure of the optimal perturbations in Couette, Poiseuille and mixing-layer shear profiles is robust and resembles localized...
متن کاملReduced description of exact coherent states in parallel shear flows.
A reduced description of exact coherent structures in the transition regime of plane parallel shear flows is developed, based on the Reynolds number scaling of streamwise-averaged (mean) and streamwise-varying (fluctuation) velocities observed in numerical simulations. The resulting system is characterized by an effective unit Reynolds number mean equation coupled to linear equations for the fl...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of Japan Society of Civil Engineers, Ser. B1 (Hydraulic Engineering)
سال: 2013
ISSN: 2185-467X
DOI: 10.2208/jscejhe.69.i_73