Does the stationary viscous flow around a circular cylinder exist for large Reynolds numbers? A numerical solution via variational imbedding

摘要

We propose an approach to identifying the solutions of the steady incompressible Navier-Stokes equations for large Reynolds numbers. These cannot be obtained as initial-value problems for the unsteady system because of the instability of the latter. Our approach consists of replacing the original steady-state problem for the Navier-Stokes equations by a boundary-value problem for the Euler-Lagrange equations for minimization of the quadratic functional of the original equations. This technique is called Method of Variational Imbedding (MVI) and in this case it leads to a system of higher-order partial differential equations, which is solved by means of an operator-splitting method. As a featuring example we consider the classical flow around a circular cylinder which is known to lose stability as early as for Re = 40. We find a stationary solution with recirculation zone for Reynolds numbers as large as Re = 200. Thus, new information about the possible hybrid flow regimes is obtained.