振动壁面对液滴碰撞动态行为的影响研究

Study on the influence of vibrating wall on the dynamic behavior of droplet impact

  • 摘要: 液滴碰撞振动壁面的现象广泛存在于自然界和工业领域。壁面振动相位会影响壁面的速度与加速度,进而影响液滴碰撞后的动态特性。因此,研究不同振动相位对液滴碰撞振动壁面动态行为的影响具有重要意义。通过高速摄像实验,观测了液滴在不同碰撞初始相位下碰撞振动壁面的过程,分析了不同振动工况下碰撞初始相位对液滴铺展和振荡特性的影响。结果表明:碰撞初始相位决定了壁面的相对位置和运动趋势;液滴铺展时间随碰撞初始相位的增大先增大后减小;最大铺展因子随碰撞初始相位的增大先减小后增大。对液滴振荡过程进行受力分析并结合振荡特性曲线发现:在90°碰撞初始相位下,液滴最大中心高度最大;碰撞初始相位对液滴稳定时间的影响较小。当壁面振幅增大时,液滴的铺展和振荡特性随碰撞初始相位变化的趋势基本不变;该变化趋势主要与振动频率有关。

     

    Abstract: The phenomenon of droplets hitting the vibrating wall widely exists in industrial production and nature, and the vibration phase of the wall affects the velocity and acceleration state of the wall, which in turn affects the dynamic characteristics of the impact droplets. Therefore, it is of great significance to determine the influence of different vibration phases on the dynamic behavior of droplets hitting the vibrating wall. The process of droplets hitting the vibrating wall of different collision initial phases was observed through high-speed camera experiments, and the influence of the initial phase of collision on the spreading and oscillation characteristics of the droplets after hitting the vibrating wall under different vibrational conditions was analyzed. The results show that the initial phase of the collision determines the relative position and motion trend of the wall, and the spreading time of the droplets increases first and then decreases with the increase of the initial phase of the collision. The maximum spreading factor decreases first and then increases with the increase of the initial phase of the collision. According to the force analysis and study of the oscillation characteristic curve of the droplet oscillation process, it is found that the value of the maximum central height of the initial phase of the 90° collision is the largest, and the initial phase of the droplet collision has little influence on the stability time of the droplet. When the amplitude of the wall vibration increases, the change of the droplet spreading characteristics and oscillation characteristics with the initial collision phase is basically unchanged. The trend of droplet spreading characteristics and oscillation characteristics with the initial collision phase is mainly frequency-related.

     

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