两种构形喷管的激光推进冲量耦合系数数值研究

提炼了由入射激光能量、能量沉积率、环境气体压强、喷管母线长度及其半顶角组合而成的圆锥形喷管无量纲因子,并将其推广到抛物形喷管的研究中。用辐射流体力学计算程序计算了4种半顶角下圆锥形和抛物形喷管的冲量耦合系数随无量纲因子的变化规律。计算结果表明:两种喷管的冲量耦合系数都存在极大值,极大值对应的无量纲因子约为0.4;无量纲因子相同时,半顶角越小,冲量耦合系数越大;同等条件下抛物形喷管的冲量耦合系数高于圆锥形喷管的冲量耦合系数。

Numerical study on impulse coupling coefficients of conical nozzle and parabolic nozzle for laser propulsion

A dimensionless factor of conical nozzle is defined combined with incident laser energy, energy deposit efficiency, ambient air pressure, generatrix length and semi-apex angle of nozzle, and it is extended to the study of parabolic nozzle. Effects on impulse coupling coefficients of conical and parabolic nozzles under four semi-apex angles are calculated by radiation gas-dynamics computational code. Results indicate that, there are the maximum impulse coupling coefficients of the two nozzles, and the corresponding dimensionless factor is about 0.4. Impulse coupling coefficient increases with the decrease of semi-apex angle at same dimensionless factor, and the impulse coupling coefficient of parabolic nozzle is greater than that of conical nozzle under the same conditions.