跃移层内沙颗粒空中碰撞的模型仿真

Simulation Model of Collision for Sand Particles in Saltation Layer

研究风沙运动的碰撞性建模问题,对控制雾霾污染有着重要的意义。风沙运动时,风沙呈现空间的非均匀分布,存在动态波动,受到外界影响,呈现较强不稳定状态。针对风沙运动碰撞分析的模型,通常假设风沙可以均匀分布且稳定状态,模型中的参数无法随着风沙流结构等因素不断变化,无法对跃移层内沙颗粒的碰撞进行有效分析,存在一定的缺陷。提出了一种颗粒流体动力学的跃移层中沙颗粒空中碰撞仿真模型,通过颗粒流体动力学方法,分析沙粒与床面碰撞、沙颗粒的空中碰撞及沙粒与气流的耦合作用,获取跃移沙粒在空中发生碰撞的概率,按照跃移层内沙颗粒空中碰撞运动的特征,塑造基于单颗沙粒动力学的沙颗粒空中碰撞仿真模型,对沙颗粒在风力作用下发生空中碰撞和达到动态稳定的过程进行仿真,为分析风沙运动提供可靠的依据。实验结果表明,所提模型获取跃移层沙颗粒运动轨迹同已知实测结果具有较高的匹配度,能够实现跃移层沙颗粒空中碰撞的有效仿真。

A simulation model of collision for sand particles in saltation layer is presented based on hydrodynamics. Through the particle hydrodynamics method, the collision of the sand with the bed surface, the collision among sand particles and the coupling between the sand particles and the air flow are analyzed, the probability of collision of sand particles with saltation in the air is obtained, and then the simulation model is established according to the movement characteristics of sand particles in the saltation layer. Finally, the collision of the sand particles in the wind and the process to achieve dynamic stable states are simulated. Simulation result shows that the proposed modal can realize the effective collision simulation of sand particles in saltation layer.