Phase-space dynamics of opposition control in wall-bounded turbulent flows

A linear process in wall-bounded turbulent shear flows

A linear process in wall-bounded turbulent shear flows has been investigated through numerical experiments. It is shown that the linear coupling term, which enhances non-normality of the linearized Navier–Stokes system, plays an important role in fully turbulent—and hence, nonlinear —flows. Near-wall turbulence is shown to decay without the linear coupling term. It is also shown that near-wall ...

Isolating Curvature Effects in Computing Wall-Bounded Turbulent Flows

The ow over the zero-pressure-gradient So-Mellor convex curved wall is simulated using the NavierStokes equations. An inviscid e ective outer wall shape, undocumented in the experiment, is obtained by using an adjoint optimization method with the desired pressure distribution on the inner wall as the cost function. Using this wall shape with a NavierStokes method, the abilities of various turbu...

Symmetry-preserving regularization of wall-bounded turbulent flows

The incompressible Navier-Stokes equations constitute an excellent mathematical modelization of turbulence. Unfortunately, attempts at performing direct simulations are limited to relatively low-Reynolds numbers because of the almost numberless small scales produced by the non-linear convective term. Alternatively, a dynamically less complex formulation is proposed here. Namely, regularizations...

Weak Dirichlet Boundary Conditions for Wall-Bounded Turbulent Flows

In turbulence applications, strongly imposed no-slip conditions often lead to inaccurate mean flow quantities for coarse boundary-layer meshes. To circumvent this shortcoming, weakly imposed Dirichlet boundary conditions for fluid dynamics were recently introduced in [4]. In the present work, we propose a modification of the original weak boundary condition formulation that consistently incorpo...

A new eddy-based model for wall-bounded turbulent flows