双电弧室轴线式电弧等离子体炬热特性试验研究

在航天领域，电弧等离子体技术是进行高温气体动力学试验的重要技术。文章对自稳弧型双电弧室轴线式电弧等离子体炬在不同参数条件下的总体热特性进行地面试验研究，并从电弧、气流和电极间热量传递的角度对热特性变化规律进行分析。结果表明:输入功率在104～300 kW变化时，热效率在49.1%～70.8%范围内与功率呈正相关性变化，射流的比焓和平均温度在输入功率为152 kW时达到最大值，分别为10.29 MJ/kg和5006 K。特定功率条件下，较小的电弧电流和较高的负载电压匹配能够获得较高的热效率，但射流的比焓和平均温度会降低。气体流量不变时，随着电弧电流的增大，热效率单调降低，而射流的比焓和平均温度依然提高。

Experimental study of the thermal characteristics of axial arc plasma torch in double arc chamber

In the aerospace field, the arc plasma technology is essential in the high temperature gas dynamics test. In this paper, the overall thermal characteristics of the axial arc plasma torch with self-sustaining arc length and double arc chambers are studied experimentally for different parameters. The characteristics including the heat efficiency, the enthalpy and the average temperature of the jet-flow, as well as the jet length are obtained, and the results are analyzed based on the heat transfer among the arc, the gas flow and the electrodes. It is shown that for a power between 104 kW and 300 kW, the heat efficiency of the plasma torch is positively correlated with the power in a range of 49.1% to 70.8%, the maximum values of the enthalpy and the average temperature of the plasma jet-flow achieved at a power of 152 kW, are 10.29 MJ/kg and 5006 K, respectively. When the power keeps constant, the heat efficiency is better with a combination of lower arc current and higher load voltage, but the enthalpy and the average temperature of the jet-flow will be lower correspondingly. When the gas flow rate keeps constant, the heat efficiency of the torch decreases with the increase of the arc current, while the enthalpy and the average temperature of the jet will rise in consequence.