基于SPH方法的风沙流运动特性研究

Research on movement characteristics of wind-blown sand flow based on SPH method

文中基于光滑粒子流体动力学(Smoothed Particle Hydrodynamics:SPH)方法,采用五次样条光滑函数,通过调节不同类型粒子光滑因子,对风沙流运动特性进行分析:1)在风沙流起动阶段,沙粒平均水平速度随高度增加而增大,同一高度处沙粒平均水平速度随时间推移而减小。2)风沙流稳定前后,沙粒数均随高度的增加而减少。3)风沙流形成过程中气体粒子在计算域中心位置产生涡流,并随着时间推移,涡流又出现在计算域中上及右下方位置。4)起沙前后气体脉动强度随摩阻风速增加而增加,随高度增加呈现不同变化。结果表明:该方法模拟精度较高,适用于解决风沙两相流数值模拟问题。

In this paper,based on the Smoothed Particle Hydrodynamics(SPH)method,the quintic spline smoothing function was used to analyze the movement characteristics of the wind-blown sand flow by adjusting the smoothing factors of different types of particles.Results showed:1)During the initiation of the wind-blown sand flow,the average horizontal velocity of sand particles increased with height,and the average horizontal velocity of sand particles at the same height decreased with time.2)Before and after the wind-blown sand flow stabilized,the number of sand particles decreased with the increase in height.3)During the formation of the wind-blown sand flow,gas particles generated vortices in the center of the calculation domain,and over time,the vortices appeared in the calculation domain again and the lower right position.4)The intensity of gas pulsation before and after sand emission increased with the increase of frictional wind speed,and changed with height.The results showed that this method has high simulation accuracy and is suitable for solving the numerical simulation problem of wind-sand two-phase flow.