光束扩展、光船倾斜和漂移对光船自由飞行演示的影响

Reversal effect of beam spreading,lightcraft pitching and lateral offset for lightcraft free flight

为了研究光船的地面演示自由飞行试验中激光束扩展、光船相对激光束的倾斜和漂移等因素对光船飞行高度的影响,采用了理论分析和数值模拟相结合的方法。分析表明,激光束的扩展将导致光船接收激光功率的减小,光船相对于光束的倾斜会影响激光的聚焦和光船推力方向,但光船的倾斜力矩不会在飞行过程中累积而使光船倾斜过大,而光船的漂移则会改变光船推力以及侧力的大小。光船飞行数值模拟仿真表明,在横向偏移扰动下,光船在没有达到最大可能高度之前将脱离光束从而失去动力。研究结果显示,减小光船的横向偏移和激光束的发散角可以有效提高光船垂直上升的高度。

Laser beam spreading, lightcraft pitching and lateral offset are some main factors which restrict the altitude that lightcraft can reach during free flight test, Analytical investigation shows that the expansion of laser beam spreading results in the reduction of the laser power received by lightcraft dramatically, and lightcraft pitching changes the direction of thrust but lightcraft pitching moment is not accumulative during flight, Lightcraft lateral offset changes the thrust and side force of lightcraft. A numerical method for lightcraft flight simulation is developed and the simulation results show that lightcraft may lose thrust before the arrival of possible altitude because of lightcraft lateral offset. Reducing lateral offset and laser beam spreading can dramatically improve the lightcraft flight height in free flight.