超声速气流磁流体加速初步实验研究

PRELIMINARY EXPERIMENTAL INVESTIGATION ON SUPERSONIC FLOW MAGNETOHYDRODYNAMIC(MHD) ACCELERATION

利用激波风洞,采用氦气驱动氩气,在平衡接触面运行方式下得到高温气体,通过在低压段注入电离种子K_2CO_3粉末,实现高温条件下导电流体的产生,设计了超声速喷管及磁流体加速实验段,采用大电容提供电能,开展了超声速气流磁流体加速初步实验研究.典型实验条件下,当喷管入口总压为0.704 9 MPa、理论平衡温度为8372.8K,喷管出口马赫数为1.5,电容充电电压为400V,磁感应强度为0.5T时,对电压电流特性、电导率、负载系数、电效率、加速效果等进行了测量或计算,主要结论有:磁场作用下的超声速气流的电导率的值大约在150S/m;磁流体加速通道负载系数约为4,电效率约为28%,平均输入功率约198kW;采用电参数测试方法对磁流体加速效果进行评估,速度增加约15.7%;超声速气流的电导率对加速通道的电效率及加速效果等有很重要的影响.

Preliminary experimental investigation on Magnetohydrodynamic （MHD） acceleration using seeded supersonic flow as working fluid was presented in the paper. Helium and argon were used as driver and driven gas, respectively, in a shock tunnel. Equilibrium contact surface operating mode was used for obtaining high temperature gas. The conductivity was obtained by adding seed K2CO3 powders into the driven section, and big capacitor was used for providing electric energy. Voltage and current characteristics, conductivity, load factor, electric efficiency and acceleration effect were measured or calculated on typical experimental condition when the nozzle entry total pressure is 0.704 9 MPa, theoretical equilibrium temperature of 8 372.8 K, nozzle outlet Mach number of 1.5, capacitance voltage of 400 V, and magnetic field strength of 0.5 T. The main results are as follows： the conductivity of supersonic flow is about 150 S/m under the existence of magnetic field; the load factor of the MHD acceleration channel is about 4; electrical efficiency is about 28%, and average input power is 198 kW; flow velocity was increased by 15.7% by means of electrical parameter measurement, and the conductivity of the supersonic flow has important influence on the electrical efficiency and acceleration effect.