Thrust Performance of Microwave Rocket Under Repetitive-Pulse Operation

An experiment was conducted on a microwave rocket (repetitive-pulse millimeter-wave-beam-powered thruster) with repetitive pulses. A thruster model with a forced-breathing system was used. The forced-breathing system supplies fresh air from the thrust wall into the thruster. The pressure histories in the thruster weremeasured and the propagation velocity of the shock wave and the thrust impulse were deduced. Results show that although the propagation velocity was identical to the result for the single-pulse operation at the first pulse, the propagation velocity increased after the second pulse. Similarly, the impulse decreased after the second pulse. The dependence of the propagation velocity of the shock wave and the thrust performance on the partial-filling rate of the fresh air was comparedwith that of the thrust-generationmodel with a forced-breathing system. The experimental results showed good agreement with those obtained using the model.