Numerical and Experimental Studies on Non Equilibrium Flows in MPD Arc Jets.

点击翻译按钮获取中文摘要

Numerical Studies on steady one-dimensional self-field MPD arc jets were conducted, taking into consideration the non-equilibrium ionization and dissociatin, and the thermal non-equilibrium. Following results were obtained :1. The current concentration is observed at the entrance and the exit of the channel in the case of argon and it is observed only at the exit of the channel in the case of hydrogen.2. The electrical conductivity is proportional to the 3/2 powers of electron temperature in the case of argon, while it is proportional to the root of that in the case of hydrogen.3. The operation of arc jets is influenced mainly by a characteristic velocity and entrance mach numbers, and also by a characteristic energy.Experimental studies on the effect of constrictor size and anode geometry (nozzle type, flare type, straight type) on the performance of arc jets were conducted using nitrogen or argon propellants. Following results were obtained :1. The electron temperature, the vibrational and rotational temperatures of molecules can be assumed in equilibrium in arc jets for the case of nitrogen propellant.2. The performance of arc jets is improved as the length and diameter of the constrictor are decreased, but the arc does not established under a critical diameter.3. The temperature and heat content of the gas ejected from arc jets are influenced by constrictor geometry but the effect of gas pressure on them is small.4. In the case of argon propellant, in the range of arc current, 50-350 A,the best performance was obtained for the flare type andhe with small diameter, operated at a low mass flow rate.