正方形截面气动外型优化仿真计算

Aerodynamic Figure Optimization of Square Cylinder by Numerical Simulation

运用计算流体力学软件FLUENT,引入雷诺应力模型求解不可压粘性流体Navier-Stokes方程,对正方形及其不同切角截面进行仿真计算.研究了正方形,切角正方形,圆角正方形三种截面的阻力,升力,俯仰力矩,Strouhal数及尾流的流动状态.仿真计算结果表明几何形状的微小变化会引起气动力系数发生很大的变化,尤其是在物体形状的变化强烈的影响到压力分布的时候,其中圆角正方形截面的气动性能最好.仿真计算结果与风洞实验结果吻合良好.

To comprehensively investigate the effect of corner modification on aerodynamic forces, this paper presents the calculations of characteristics of a square sectioned cylinder with sharp,chamfered or rounded corners in two dimensional incompressible uniform cross flow by using RSM method of FLUENT. The numerical simulation focused on investigating the characteristics of the drag force, lift force,moment force,Strouhal number and typical flow patterns. It is found that the incidence of sepa- ration is often rather sensitive to small change in the shape of the solid body, particularly when the pressure distribution is strongly affected by this change in shape. So wind loading can be reduced by controlling the separated flow through modifying corner shapes. The numerical simulation results are in good agreement with the experiment results and rounded corners has the best aerodynamic quantities.