Effect of nozzle geometry on the performance of laser ablative propulsion thruster

摘要

The performance of "ablation mode" laser propulsion thrusters can be improved obviously by nozzle constraint. The nozzle geometry of "ablation mode" laser propulsion thrusters has been studied experimentally with CO_2 lasers. Experimental results indicate that the propulsion performance of cylindrical nozzle thrusters is better than expansionary nozzle thrusters at the same lengths. The cylindrical nozzle thrusters were optimized by different laser energies. The results show that two important factors, the length-to-diameter ratio α and the thruster diameter to laser-spot diameter ratio β, affect the propulsion performance of the thruster obviously. The momentum coupling coefficient C_m increases with the increase of α, while C_m increases at first and then decreases with the increase of β.