不同磁感应强度下的磁流体加速实验研究

利用基于激波风洞的磁流体动力技术实验系统,设计了超声速喷管和分段法拉第型试验段,选用合理的电场及磁场方案,开展了不同磁感应强度下的磁流体加速实验研究.当激波管高压段压力1.2 MPa、低压段压力500 Pa,电容充电电压为400 V时,得到的主要实验结论如下:随着磁感应强度增大,加速通道电极间电压增加,电流降低,单个电极的输入功率降低,负载系数略有降低,电效率略有升高；当磁感应强度分别为0.5T、1T、1.5T时,#10电极处超声速气流的电导率分别约为181S/m、81S/m和50 S/m,利用#20电极开路电压的方法评估出口速度增量分别约为16.1％、14.7％、14.3％.电导率对输入功率的影响较大,提高加速效果需要同时提高气流的电导率和通道的电效率.

Experimental Investigation on MHD Acceleration under Different Conditions of Magnetic Induction

MHD acceleration technology is of great hope in application. In this paper, with a MHD experimental system based on shock tunnel being used, the supersonic nozzle and test section (segmented Faraday accelerator) are designed as well as reasonable electric field and magnetic field facilities. Experiments under different magnetic induction are carried out. Under the conditions of 1.1 MPa driver pressure, 500Pa driven pressure and 400 V capacitance voltage, some results are obtained as follows: With the increase of the magnetic field, the voltage at electrode pair #10 rises, while the current is decreased, the input power and the load factor are decreased. When magnetic inductions are differently as 0.5 T, 1 T and 1.5 T, the conductivities of supersonic airflow are about 181 S/m, 81 S/m and 50 S/m respectively, and the increasing rates of outlet speed are estimated to be 16.1%, 14.7% and 14.3% by evaluation method of using open circuit voltage at electrode pair #20. The conductivity of supersonic airflow has an important effect on acceleration, and both the enhancements in electric conductivity and in efficiency are simultaneously needed to improve MHD acceleration.