Propulsive characteristics of water droplets for multi-pulse laser propulsion

Time-resolved force sensing technique was applied to the study on propulsive characteristics of water droplets for multi-pulse TEA (transversely excited at atmospheric pressure) CO2 laser propulsion. Laser-driven blast waves and associated flow dynamics in impulse generation processes of ablation of water droplets were studied through schlieren visualization. Experimental results show that coupling coefficient and specific impulse decrease as the interval between laser pulses and pulse numbers increase. The maximum speed of blast wave in the opposite and same direction of laser propagation is 10 km/s and 7 km/s, respectively. Time-resolved force and schlieren visualization results indicate that vaporization and blast waves dominate the impulse generation processes of water droplets for las