中文摘要：

直接从颗粒受力和运动出发,基于直接模拟蒙特卡洛（DSMC）方法建立颗粒碰撞模型,模拟声场中颗粒的碰撞过程,通过改变模拟条件,探讨DSMC方法中的特征参数（取样颗粒的数目权重、网格数目、时间步长）对颗粒碰撞率和计算时间的影响.结果表明：频率越大,颗粒容积份额变化越迅速,颗粒空间分布越不均匀;数目权重的增加对颗粒碰撞率影响较小,而对计算时间的影响显著,使其迅速减少;网格数目增加,碰撞率降低,计算时间则先迅速降低,随后在低频时基本不变,高频时略有上升.研究还发现：随着碰撞时间步长的增加,低频声场中碰撞率单调增加,高频声场中碰撞率先增加而后出现波动;碰撞时间步长的增加将引起计算时间减少,减少量在碰撞步长较小时最为明显.

英文摘要：

An inter-particle collision model was established based on the direct simulation Monte Carlo（DSMC）method as well as the force analysis and the motion equation.The collision process of the particles in acoustic field was examined.Through changing the numerical simulation conditions,the influences of the characteristic parameters,such as the weight value of the number of sampling particles,the cell number and the time-step size used in DSMC method,on the particle collision rate and computational time were discussed.The results show that the higher the acoustic frequency is,the more rapidly the particle volume fraction changes and the more unevenly the particles are distributed in space.The increase of the weight value of the number has a small effect on the collision rate,but it significantly reduces the computational time.As the cell number increases,thecollision rate decreases,whereas the computational time decreases rapidly at first and then almost keeps constant at lower acoustic frequency and increases slightly at higher acoustic frequency.It is also found that as the time-step size for determining the inter-particle collision increases,the collision rate increases monotonously at lower frequency,while it increases at first and then fluctuates at higher frequency.The increase of the time-step size results in the decrease of the computational time and the decrease is more obvious with a smaller time-step size.