低功率氩电弧加热发动机的数值模拟

采用可求解可压缩流动与传热的全速度SIMPLE算法,对低功率氩电弧加热发动机内部的传热与流动进行了数值模拟,获得了电弧加热发动机内的温度、速度、马赫数及流线分布。计算结果表明:电弧加热发动机内最高温度出现在阴极下游附近中心轴线处,这是因为电弧在阴极表面收缩形成阴极弧点,从而焦耳热成为该高温区的主要加热机制;沿着发动机中心轴线,气体温度和速度开始时随着距阴极距离的增加而迅速增加,然后在等离子体流向喷管出口的过程中,气体温度和速度逐渐下降。此外还详细考察了弧电流变化对电弧加热发动机内部传热与流动特性的影响,计算获得的发动机流量和比冲与实验结果基本一致。

Numerical modeling of low-power argon arcjet thruster

In this paper, modeling study is performed to reveal the plasma flow and heat transfer characteristics of the low-power argon arcjet thruster. The all-speed SIMPLE algorithm is used for the solution of the governing equations. Computed results are presented concerning the temperature, velocity, Mach number and streamline distributions within the thruster nozzle and concerning the current density distributions on the anode-nozzle surface under typical operating conditions. It is found that the heating of the gaseous propellant takes place mainly in the cathode and constrictor regions and the highest plasma temperature appears at the location near the cathode tip where the current density assumes its maximum value. The plasma axial-velocity and temperature profiles along the nozzle axis incr