直排型连续波DF/HF化学激光器气流通道模型中氮作引射气的相变问题

为了研究直排型连续波DF/HF化学激光器的启动特性,建立了一套化学激光器气流通道双喷管小型实验模型。以氮和氦作为引射介质,采用两种面积比的引射喷管,进行了启动实验。实验表明,当以氮作为引射介质,采用大面积比的引射喷管进行实验时,实验数据与1维理论计算结果相差很大。分析认为,该次实验中,在引射喷管内剧烈地膨胀后,部分N2已经发生相变,理论计算采用的1维定常流处理法已经不再适用。计算表明,连续波DF/HF化学激光器中的光腔燃料和副稀释剂He不会发生相变,但当以N2作副稀释剂时,副稀释剂喷管面积比不能过大。

Phase change of nitrogen as primary flow in gas channel model of directly drained CW DF/HF chemical laser

To study the starting characteristic of directly drained CW DF/HF chemical laser (DDCL), a double-nozzle small-scale model of DDCL gas channel was set up, and a series of experiments without secondary flow was conducted with nitrogen and helium as primary flow respectively. The data of experiment, which is conducted with nitrogen and primary nozzles of large area ratio, are far away from the theoretical result. It is believed that, a part of nitrogen has phase transition while it is expanding in the experim...