中文摘要：

采用有限体积法计算了均匀来流条件下圆柱体和正四面体颗粒的低雷诺数三维绕流流场,得到了颗粒在不同来流方向下的速度分布、压力分布,分析了其阻力特性。结果表明,非球型颗粒的在风场中的绕流阻力大小受来流方向的影响明显,在特定方向阻力最大,这与绕流后的剪切层结构有关。通过比较发现,以往非球型颗粒阻力经验公式给出的只是单一来流方向时的阻力值,而非平均值。根据计算结果给出了新的拟合非球体阻力系数计算公式,可以更准确地估算非球型风沙颗粒各来流方向的平均阻力值。

英文摘要：

Three dimensional numerical flow field around a cylinder or tetrahedron-shaped blown sand particles are simulated.The flow velocity and pressure distributions with different inflow condition are computed and analyzed.It is shown that the drag coefficient is strongly influenced by inflow direction and the maximum drag occurs at a certain inflow angle as a result of different coherent structure.The drag coefficient value previously calculated by using empirical formula is only for a single inflow direction but not an average value for all directions.This paper presents an improved formula for calculating average drag coefficient of non-spherical sand particles.