高频调幅交变电磁场金属液滴悬浮振荡的 3 维数值模拟

采用有限元方法模拟高频调幅交变电磁场以及液滴内流体流动, 金属液滴自由界面的追踪采用任意拉格朗日欧拉(arbitrary Lagrange-Euler, ALE)方法. 数值模拟得到了高频调幅交变电磁场、金属液滴内部液体流动和液滴表面形变的动态行为. 数值结果表明: 在高频调幅交变电磁场中, 金属液滴所受洛伦兹力集中在液滴内部近表面区域, 液滴受近似表面力的洛伦兹力激励; 在表面张力和重力的共同作用下呈周期性振荡, 液滴的振荡幅度起伏变化, 具备参数振荡特征. 对液滴振荡的频谱分析结果显示, 液滴振荡的主频和高频调幅交变电磁场的调制波频率相同, 在其倍频处也会出现较大峰值, 液滴振荡的频谱特征与高频调幅交变电磁场中金属液滴所受洛伦兹力的频率特性吻合.

Three-dimensional numerical simulations of suspended metal droplet oscillations in high-frequency,amplitude-modulated,alternating electromagnetic fields

A three-dimensional numerical model for the oscillations of suspended metal droplets in a high-frequency, amplitude-modulated electromagnetic field is built. Numerical simulations of a suspended metal droplet oscillating in the high-frequency, amplitude-modulated electromagnetic field are also performed. The high-frequency, amplitude-modulated electromagnetic field and the flow of the liquid metal droplet are simulated via the finite element method. The free surface of the liquid metal droplet is calculated using the arbitrary Lagrange-Euler (ALE) method. The high-frequency, amplitude- modulated electromagnetic field; the flow of the liquid metal droplet; and the free surface of the oscillating droplet are determined numerically. The shape of the oscillating droplet, as obtained via the numerical simulation, is in good agreement with the experimental results. Furthermore, frequency analyses based on the numerical results of the oscillation of the droplet are in good agreement with the theoretical calculations.