Numerical Simulation of Sudden Contraction Flow for Viscoelastic Fluids with the Lattice Boltzmann Method

摘要

In this paper, based on the lattice Boltzmann method (LBM) and the Oldroyd-B model, the decoupled solving method for the incompressible Navier-Stokes equation and advection-diffusion constitutive equation and the boundary processing formats are given. The flow of viscoelastic fluid in the planar 3:1 contraction channel is simulated. For different Reynolds numbers Re, Weissenberg numbers Wi and viscosity v_s, the streamline patterns, the positions of vortex center and the length of vortex are obtained, and the influences of these parameters on flow behavior are discussed. The numerical results also present that the decoupled solving method is feasible and the LBM has fine accuracy and stability.