CAREER Plasma Heat Transfer: Research and Education

热等离子体越来越多地应用于制造和材料加工中，高温促进了能量的传递，自由电子和离子为化学反应提供了环境。典型的应用是等离子喷涂、化学气相沉积、烧结、合成、螺化、废物销毁和网状制造。在所有这些应用中，等离子体的热传输是决定产品质量的关键。这项建议的工作是发展对等离子体中传输过程及其与固体/液体表面相互作用的基本原理的更多理解，并为传热建立模型和相关性。由于电鞘层靠近固体表面，等离子体到固体表面的热传递过程比游离化气体要复杂得多。提出的工作涉及热等离子体中运动的单个粒子的传热研究。中性气体、电子和离子的流动将被测定。详细分析了电鞘、带电粒子的产生和复合以及粒子的熔化。用任意拉格朗日-欧拉方法确定熔点。数值预测将与感应等离子体中粒子运动的文献中的实验测量和气体流动中液滴的可视化进行比较。液滴形状变形的趋势将被预测为雷诺数和韦伯数以及液/气粘度和密度比的函数。

Abstract - CTS-9733369 Milind A. Jog Thermal plasmas are increasingly used in manufacturing and material processing where the high temperatures facilitates energy transport and the free electrons and ions provide an environment for chemical reactions. Typical applications are plasma spraying, chemical vapor deposition, sintering, synthesis, speroidization, waste destruction, and net shape manufacturing. In all of these applications, the heat transport from the plasma is critical in determining the quality of the product. This proposal work is to develop an increased understanding of the fundamentals of the transport processes in the plasma and its interaction with solid/liquid surfaces, and to develop models and correlations for the heat transfer. The processes associated with heat transfer from the plasma to a solid surface are significantly more complicated than for unionized gases because of the electrical sheath which lies close to the solid surface. The proposed work involves the study of the heat transfer to a single particle moving in a thermal plasma. The flow of the neutral gas, the electrons, and the ions will be determined. Detailed analyses of the electric sheath, the production and recombination of charged particles, and the melting of the particle will be made. The melting front will be determined using the Arbitrary Lagrangian Eulerian method. The numerical predictions will be compared to experimental measurements in the literature of particle motion in induction plasmas and to visualizations of liquid droplets in gas flows. Trends in droplet shape deformation will be predicted as functions of Reynold's and Weber numbers and liquid/gas viscosity and density ratios.