关键词: 非定常流, N-S方程, 有限元素法

Abstract:

This paper presents a numerical method for solving the unsteady, incompressible Navier-Stokes equations in terms of primitive variables. The method is composed of a penalty Galerkin finite element procedure for spatial discretization, in conjunction with an improved trapezoidal rule for time integration. A self-adaptive time step technique is imposed into the time marching to make the calculation most costefficient.The entire process beginning from vortex shedding through the formation of Karmann vortex street for impulsively started circular cylinder at Re =100 and 200 are simulated, and the results are compared with those obtained by other methods.

Key words: uneteady flow, N-S equation, finite element