空气中不同间隔凹坑面的减阻性能仿真

Numerical Simulationof Drag Reduction of Dimple Surface with Different Spacing in Air

仿生非光滑凹坑面减阻技术具有重要的经济价值和军事价值,但目前相关理论不完善。凹坑面减阻效果与其结构形态、来流速度、流体介质等有关,为了进一步分析凹坑面的减阻效果及减阻机理,对具有凹坑变间隔排列非光滑面在空气介质不同速度下的流场进行数值仿真计算。结果表明,模型9(r=0.5s=h=0.25mm,a=5mm)达到局部最优减阻效果,在来流速度为6m/s时,总减阻量为25.927%。最后分析了间隔对凹坑面减阻影响。间隔长度相对于凹坑面尺寸有个合适数值。

Currently, bionic non-smooth surface drag reduction technology with significant economic value and military value is still imper- fect. Generally, dimple structure, flow velocity, fluid medium and other factors are related to the dimple surface drag reduction. In order to further analyze the pit surface drag reduction, the numerical simulation was carried on the flowing of dimple non-smooth surface with dif- ferent spacing in air. The results show that this kind of unsmooth surface with dimples （r = 0. 5s,h = 0. 25mm,a = 5ram） has a good local optimum drag reduction effect on flow velocity ranging from 6m/s to 15m/s, and it has the best reducing ability （25. 927% ） at the velocity of 6m/s. Finally, the theory of the drag reduction and the impact of the dimples drag reduction factors （ different spacing） were analyzed. Interval length relative to the concave surface size has an appropriate value.