Application of a second-order projection method to the study of shear layers

Abstract

In this paper we apply a second-order projection method for the time-dependent, incompressible Navier-Stokes equations to the study of shear layers. The algorithm represents a higher-order extension of Chorin's projection algorithm. In Chorin's algorithm one first solves the Navier-Stokes equations ignoring the pressure term and then projects the resulting velocity field onto discretely divergence-free vector fields. Our method introduces more coupling between the diffusion-convection step and the projection to obtain second-order temporal accuracy. Furthermore, the algorithm incorporates a second-order Godunov method that provides a robust treatment of the nonlinear terms at high Reynolds number. These features combine to give a method that is second-order accurate for smooth flows and remains stable for singular initial data such as cortex sheets, even in the limit of vanishing viscosity. 9 refs., 2 figs.