Experimental Study on the Effect of Structural Geometry of “Ablation Mode” Thruster on Propulsion Performance

The propulsion performance for “ablation mode” laser propulsion can be improved obviously under nozzle constraint condition. The effect of the structural geometry of the “ablation mode” laser propulsion thruster has been studied experimentally with CO2 lasers. Experimental results indicate that the propulsion performance of the cylindrical nozzle thruster is better than that for the expansionary nozzle thruster if their lengths are the same. The cylindrical nozzle thrusters are optimized by experiments using different laser energies. The results show that there are two important factors affecting the propulsion performance of cylindrical nozzle thrusters: the length‐to‐diameter ratio β and the thruster diameter to laser‐spot diameter ratio α. The momentum coupling coefficient Cm increases with the increase of β, while Cm increases at first and then decreases with the increase of α.