Experimental Investigation of the Pressure Characteristics in Air-Breathing Laser Propulsion

摘要

Keeping the single pulse energy of the CO{sub}2 laser constant, the impulse coupling coefficients of air-breathing laser propulsion are measured at various air pressures using a high precision impact pendulum system and the corresponding altitude characteristics. The results show that the impulse coupling coefficient is about 35dyne.s/J with less than 5% fluctuation when the air pressure varies from 2.8 × 10{sup}4 Pa to 1 × 10{sup}5 Pa and the altitude from Okm to 10km. When the air pressure is less than 2.8 × 10{sup}4 Pa and the altitude is greater than 10km, the impulse coupling coefficients decrease following a quadric curve. At a pressure of 1 × 10{sup}3 Pa and altitude of 31km, the impulse coupling coefficient is only 9.7dyne.s/J i.e. a drop of 75%. These results, which can be explained as due to the angle of the thrust, are consistent with those of German work using a parabolic device.