振动壁面对液滴冲击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: 液滴撞击振动壁面现象广泛存在于工业生产和自然界中,壁面振动相位影响壁面速度以及加速度状态,进而影响冲击液滴的动态特性。因此,确定不同振动相位对液滴撞击振动壁面动态行为的影响有重要意义。通过高速摄像实验观测液滴撞击不同碰撞初始相位振动壁面的过程,分析在不同振动工况下,碰撞初始相位对液滴撞击振动壁面后的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相对位置和运动趋势,液滴铺展时间随着碰撞初始相位的增加先增大后减小。最大铺展因子随着碰撞初始相位的增加先减小后增大。根据液滴振荡过程受力分析和研究振荡特性曲线,发现90°碰撞初始相位最大中心高度的值最大,液滴碰撞初始相位对液滴稳定时间影响较小。当壁面振幅增加时,液滴铺展特性和振荡特性随初始碰撞相位变化的趋势基本不变;液滴铺展特性和振荡特性随初始碰撞相位变化的趋势主要与频率有关。

     

    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 center 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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