高频调幅交变电磁场作用下扁平附着液滴谐振形成机理及特性

It has not been seen in literature before that amplitude modulated high frequency alternating electromagnetic field can bring about multiple modal resonant shape oscillation of a metal droplet. This method can be extended to the noncontact treatment technology such as suspension smelt and measurement of the surface tension and the viscocity of the high temperature frused metal. This item intend to probe into, by theoretical and experimental method, the mechanism that amplitude modulated high frequency alternating electromagnetic field actuates the drop into multiple modal resonant shape oscillation, laying special emphasis on the mechanism that the surface tension and the electromagnetic force, acting on the droplet, actuate the drop into resonant shape oscillation. Experiments will be done to observe the flow pattern and to measure the flow field when amplitude modulated high frequency electromagnetic field actuates the drop into multiple modal resonant shape oscillation. Based on the Mathieu equation, the stability analysis on the oscillation of the drop resulted in by the electromagnetic force in the amplitude modulated high frequency electromagnetic field will be done. Mathematical model will be established to depict the internal flow induced by the resonant shape oscillation of the drop actuated by the amplitude modulated high frequency alternating electromagnetic field. Accurate model for surface tension and the electromagnetic force acting on the drop by the amplitude modulated high frequency electromagnetic field and the corresponding numerical method will be proposed to conduct quantitative numerical analysis. Through these studies, the main factors affecting on the characteristics of the droplet resonant shape oscillation will be acquired quantitatively, and the emergence of multiple modal resonant shape oscillation of the drop will be able to be forecasted. The research achievement will have important application prospects in metallurgy and material technology research, and will promote the development of the drop dynamics study.

施加高频调幅交变电磁场，使扁平附着金属液滴产生多种模态谐振，迄今未见文献报道，可推广应用于解决悬浮熔炼和高温熔融金属液表面张力和粘度测定等非接触处理技术相关问题。本项目旨在以理论和实验手段研究高频调幅交变电磁场激发液滴产生谐振的机理,侧重分析液滴受变化的表面张力和电磁力作用激发液滴产生谐振的力学机制。拟开展高频调幅交变电磁场作用激发液滴产生多种模态谐振行为的实验观测和测量。基于Mathieu方程，进行液滴受高频调幅交变电磁场电磁力作用产生振荡时的稳定性分析。建立数学模型，描述液滴受高频调幅交变电磁场作用激发谐振行为的内部流动过程，提出准确反映高频调幅交变电磁场对液滴作用的电磁力和表面张力模型，采用并改进相应的数值模拟方法，进行定量分析。通过上述研究，将定量分析主要因素对液滴振荡特性的影响，预测液滴多种模态谐振的发生。本项研究在冶金、材料等技术的研究中将有重要应用，并将促进液滴动力学的发展。

附着在不润湿的表面上的扁平状金属液滴施加高频调幅交变电磁场，会使液滴产生形态振荡，激发液滴产生多种模态的谐振。上述方法可推广应用于，解决悬浮熔炼和高温熔融金属液表面张力和粘度等参数测定的非接触处理和测量技术中相关问题。通过施加高频调幅交变电磁场，使液滴产生形态振荡，激发液滴产生多种模态的谐振，是激发液滴产生多种模态谐振的一种新方法，具有应用前景。.项目主要开展了高频调幅交变电磁场作用下附着液滴的谐振实验，开展了交变电磁场作用下附着液滴谐振的数值模拟计算，对交变电磁场作用下附着液滴谐振进行了理论分析，并初步开展了高频调幅交变电磁场作用下悬浮液滴谐振的实验和数值模拟研究。实验得到了高频调幅交变电磁场作用下附着液滴产生谐振的高频调幅交变磁场强度和调幅频率，以及对应的振动模态。数值模拟计算得到了交变电磁场作用下附着液滴产生谐振的磁场强度和调幅频率，以及对应的振动模态。通过交变电磁场作用下附着液滴谐振的理论分析得到了其控制方程。研究结果表明，在外加的激励液滴产生谐振的交变磁场的磁场强度和频率相图中，液滴各模态谐振出现区域界限都近似成“V”字形，“V”字形的谷底对应值即为激发相应模态振荡的临界值。部分模态出现了分频和倍频的特征，因此，液滴在高频调幅及低频交变电磁场作用下产生谐振的机理与非线性理论中基于马修方程（Mathieu-type equation）的参数振动行为（parametric oscillation）相似，交变电磁场作用下附着液滴谐振机理的理论分析结果也表明其控制方程是一种典型的参数振动的控制方程。.本项研究在冶金、材料等技术的研究中将有重要应用。对液滴振荡乃至破碎现象的研究具有理论价值，将促进液滴动力学研究的发展。