低雷诺数下附属棱柱的圆柱绕流减阻

目前圆柱绕流减阻方案的探索一直是绕流研究的热点,有关棱柱作为扰流柱对圆柱减阻效率影响的研究却较少.基于不可压缩黏性流动Navier-Stokes控制方程,利用OpenFOAM对附属棱柱下圆柱绕流问题进行数值模拟.在圆柱上游或下游设置双扰流棱柱,研究了雷诺数为200时不同角度、间距比的棱柱对其升力、阻力系数和涡脱频率的影响.结果表明:附属棱柱能有效改善圆柱表面的压力分布,降低压差阻力;上游设置棱柱时对圆柱的减阻效率可以达到37.21％,较下游设置棱柱的减阻效率更高;下游设置棱柱时对圆柱升力的抑制效率高于上游棱柱,可以达到99.86％;上下游同时设置棱柱时对圆柱升力、阻力的抑制效果能得到进一步提高,较单圆柱平均阻力系数可以降低54.63％,升力系数可以降低99.94％.

Study on drag reduction of flow past a circular cylinder attached prisms at low Reynolds number

At present, the research on the scheme of reducing drag around a circular cylinder has always been a hot topic. But there are few studies on the effect of prisms as pin fins on the drag reduction efficiency of cylinder. Based on the Navier-Stokes equations of incompressible viscous flow, numerical simulation of flow past a circular cylinder attached prisms was investigated by using OpenFOAM. A circular cylinder with double prisms placed upstream or downstream, the effects on lift coefficient, drag coefficient and Strouhal number of prisms with different angles and relative gap from the wall have been investigated at Re=200. The numerical results show that the attached prisms can effectively improve the pressure distribution on the cylinder surface and reduce the pressure drag. The drag reduction efficiency of the upstream prisms for cylinder can reach 37.21%, which is higher than that of the downstream prisms. When the prisms are set in the downstream of the cylinder, the restraining efficiency of the cylinder lift is higher than that in the upstream, which can reach 99.86%. When the prisms are placed upstream and downstream simultaneously of the cylinder, the restraining effect on the lift and drag of the cylinder can be further improved. Compared with single cylinder, the average drag coefficient can be reduced by 54.63%, and the lift coefficient can be reduced by 99.94%.