Plasma has the characteristics of high temperature, high enthalpy and high chemical activity. It is an ideal preparation method in the fields of micro-nano material preparation and plasma spraying. However, the discharge area of single plasma torch is small, and the high temperature area of plasma is limited, which makes the residence time of material particles in the high temperature area of plasma short, limits the heating and melting effect of material particles, and affects the preparation efficiency and coating performance. For this reason, we designed an RF-DC hybrid plasma torch. Using the secondary development of FLUENT software, a user-defined function C++ program for calculating the hybrid plasma was written, and the physical field distribution in the hybrid plasma torch was calculated. The results show that the hybrid plasma torch stably extends the plasma length and increases the residence time of the material particles in the high temperature region of the plasma, thereby optimizing the heating and melting process of the material particles. This provides theoretical guidance for optimizing and upgrading plasma generators and their applications in industry.

Numerical simulation, Material particles, RF-DC hybrid-connected thermal plasma;Temperature distribution

热等离子体具有高温、高焓和高化学活性等特征，在微纳米材料制备和热等离子体喷涂等领域是理想的制备手段。然而，热等离子体炬放电区域小、高温区有限，使得物料颗粒在热等离子体高温区滞留时间短，限制了物料颗粒加热和熔融效果，影响了制备效率和涂层性能。为此，设计了一种射频-直流(RF-DC)串联热等离子体炬，采用二次开发的 FLUENT软件，编写了用于计算这种串联热等离子体的用户自定义函数 C++程序，计算得到了这种串联热等离子体炬内的各物理场分布。结果表明：串联热等离子体炬稳定扩展了热等离子体长度，增加了物料颗粒在热等离子体高温区的滞留时间，从而优化物料颗粒的加热和熔融过程。这为优化、升级热等离子体发生器及其在工业中的应用提供了理论指导。

数值模拟, 物料颗粒, 射频-直流串联热等离子体, 温度分布