不同雷诺数下圆柱绕流仿真计算

Numerical Simulation of the Flow Around a Circular Cylinder at Varies Reynolds Number

应用计算流体力学软件Fluent对不种雷诺数下(亚临界区、超临界区、极超临界区)的圆柱绕流进行仿真计算。采用大涡模型(Large-eddy simulation),不可压缩的Navier-Stokes方程,计算了三维圆柱绕流的气动力特性。系统分析了涡脱落形态,阻力系数,Strouhal数随雷诺数的变化情况。数值计算结果表明流动呈明显的三维特性,在105≤Re≤106时出现阻力危机现象,从亚临界区、超临界区到极超临界区,涡脱落形态由规则到不规则再到规则。

Flow over a cylinder is a fundamental fluid mechanics problem of practical importance. This paper presents the calculations of characteristics of a rigid single circular cyclinder in two or three dimensional incompressible uniform cross flow by using Lamber or Largeeddy simulation method of FLUENT. The numerical simulation focused on investigating the characteristics of the drag coefficient , Strouhal number and the typical flow patterns with the Reynolds number from 1 to 10^7. It is found that under the high Reynolds number the flow around the cylinder obviously appears three dimensional characteristics. There is sudden decrease in Cd for 10^5≤Re≤10^6 ,The numberical results are good agreement with the previous experiment results.