二维凹坑型非光滑单元体深度对减阻性能的影响分析  

Influence analysis of 2Ddimple concave non-smooth units' depth on drag-reduction performance

作　　者：张靖龙[1] 谢金法[1] 李洋洋[1] 

机构地区：[1]河南科技大学车辆与交通工程学院,河南洛阳471003

出　　处：《中国农机化学报》2016年第4期44-48,共5页Journal of Chinese Agricultural Mechanization

基　　金：国家863项目(2012AA111603)

摘　　要：应用计算流体力学(Computational Fluid Dynamics,CFD)方法,对比相同条件下不同深度二维凹坑型非光滑单元体减阻性能的差异,从中分析非光滑单元体的深度减阻性能的影响。经仿真发现:当来流速度为7m/s时,深度为0.2mm的凹坑型非光滑单元体减阻率为15.97%,深度为0.4mm减阻率达到最大值18.08%,而深度为0.6mm时,减阻率出现负值,说明无法实现减阻。最后对二维凹坑型非光滑单元体的减阻原理进行了分析,发现在凹坑中形成反向旋转的涡,从而形成"涡垫"效应,将空气与壁面的滑移摩擦变为滚动摩擦,从而使摩擦阻力有效减少。In application of CFD to compare the difference of drag-reduction performance of 2Ddimple concaves at different depth.In the simulation,when the flow velocity is at 7m/s,the dimple concave non-smooth units at the depth of 0.2mm get the drag-reduction rate of 15.97%,at the depth of 0.4mm get the maximum drag-reduction rate of 18.08%,while at the depth of 0.6mm,the drag-reduction rate is negative,that indicates drag-reduction cant be achieved at that depth.Finally,the drag-reduction mechanism of the 2D dimple concave is analyzed that there is a rotating vortex in the concave,thus forming a‘vortex cushion＇effect,which changes sliding friction into rolling friction,so that the surface friction drag reduces efficiently.

关 键 词：计算流体力学 凹坑型非光滑单元体 深度 减阻性能 

分 类 号：U461.1[机械工程—车辆工程]