水平平面声波对重力场中PM_(2.5)颗粒作用的数值模拟及实验研究

Experiments and Numerical Simulation of the PM_(2.5) Driven by Level Sound Wave in Gravitational Field

将空气对PM2.5的阻力特性考虑在内,建立了水平平面声波对重力场中PM2.5颗粒动力学特性影响的数学模型,以探讨声场和重力场双重作用下PM2.5颗粒的运动情况。模拟了整周期时刻和整波长位置平面波声场内压力的分布情况。颗粒在不同初始位置的速度及颗粒在初始位置为整波长位置的位移情况。通过模拟计算发现:颗粒初始位置的不同造成了颗粒初始速度的大小、方向不同;声场的强度、频率是影响颗粒运动的重要条件;颗粒的水平位移和垂直位移的综合结果是颗粒螺旋型下落,这个空间是颗粒碰撞的有效空间。可视化实验验证了模型的可行性。

A model that describes the movement of PM2.5 driven by level sound wave in gravitational field was suggested, and the resistance to PM2.5 brought by air was considered in this model. The pressure distribution during the whole period and the whole wavelength in the sound field were simulated, also including the speed tendency when particle at different positions and its displacement situation when PM2.5 located at the whole wavelength position. From the model some conclusions were drawn： the different initial positions would lead to different speed and orientation to PM2.5; intensity and the frequency of sound field are important factors that affect the movement of particles; the combination of level displacement and vertical displacement would result in spiral movement of PM2.5 and this space is the effective space for collision. Visual experiments verified that the model is suitable.