风沙运动中沙粒阻力的数值研究

 对雷诺数Re≤300下单个圆球的阻力和两个前后不同距离的圆球之间的相互干扰对阻力特性的影响采用数值模拟的方法进行了研究。其中，单球的计算主要是为了检验方法的可靠性，并为后面双球干扰的计算提供一个基础。单球计算结果表明：单球的阻力系数值和流动特性与文献中的研究结果很符合。双球计算的结果表明：后球对前球的阻力影响很小，而前球对后球的影响则非常大，计算中后球的阻力最小只有单球的30%。这种影响与圆球的雷诺数和两球之间的距离都有关系。

Numerical Study on Drag Force of Blown Sand

The computation of the drag coefficient of a single sphere in blown sand was carried to check the computation of double spheres placed in the flow direction at Reynolds number Re≤300, and the influence of two shperes’ interference on the drag characteristics has been investigated by the numerical simulation method. Numerical results of the single sphere accorded well with results in literatures; results of the double spheres indicated that the influence of the posterior sphere on the anterior sphere is very weak, but the influence of the anterior sphere on the posterior sphere is very strong. For example, the drag coefficient of the posterior sphere is only 30% of the single sphere when the two spheres are close. The interference between two spheres depends on their distance and the Reynolds number.