在超音速化学氧碘激光器的设计中, 为了削弱光腔部分的化学反应放热对激光器出光的负面效应, 在光腔部分通常加入一扩张角。为了研究这一扩张角对激光器内流场的作用, 根据kW级超音速化学氧碘激光器的实验平台, 数值模拟了激光器内超音速混合喷管至光腔部分的流动过程, 解析了光腔扩张角对内流场的流动参量和化学增益的影响, 从维持压强和温度稳定性方面比对分析了不同扩张角度的性能, 并探索了喷管高度和扩张角之间的规律。结果表明: 此kW级超音速化学氧碘激光器的合理光扩张角度为4.5°。

To avoid heat shocks in the operation, the choice of resonator expanding angle should be considered in the design of the supersonic chemical oxygen-iodine laser. The influence of the expanding angle on inner flow field of the laser has been numerically investigated based on a kilowatt laser experiment setup. To define a proper expanding angle which has the ability to keep constant pressure and temperature through the resonator, different angles have been analyzed in the view of flow parameters and chemical gain. The relationship between the nozzle height and expanding angle has also been studied. Numerical result shows that the proper expanding angle of the kilowatt is 4.5°.