パルス作動MPDスラスタ内のプラズマ挙動に関する数値計算

抄録

Numerical investigation on the transient phenomena of the plasma flows in a pulsed MPD thruster has been conducted. Argon is used as a propellant and the mass flow rate is fixed to 0.8g/s. Just after the discharge is initiated, a shock wave is induced in the thruster due to the intensive Joule heating around the cathode, and then the shock wave is propagated to a downstream region at a speed of about 3,000m/s. This numerically evaluated velocity of the shock propagation agrees with the shock velocity derived from the Rankine-Hugonio relation including an electromagnetic effect. When the discharge duration time is too small, for example, 120μs, the specific impulse is almost half as long as that in the steady operation due to low propellant utilization. To enhance propellant utilization efficiency, the discharge duration of the pulsed MPD should be large (> 600μs).