为了研究扩压器喉道长度对直排型连续波DF/HF化学激光器起动特性的影响,建立了一套化学激光器气流通道双喷管小型实验模型。在无二次流的条件下,通过选用喉道长度不同的扩压器进行实验,分别得到对应的起动压力和工作压力,并将起动压力和工作压力的大小作为评价扩压器喉道长度优劣的依据。实验数据显示,对于该特定结构的直排型DF/HF激光器气流通道双喷管实验模型,扩压器喉道最佳长度为等效直径的17倍。 In order to study the effect of diffuser throat length on the start-up characteristics of an inline continuous-wave DF / HF chemical laser, a small experimental model of a double nozzle for a chemical laser gas flow channel was established. Under the condition of no secondary flow, the experiment was conducted by choosing diffuser with different throat length, and the corresponding starting pressure and working pressure were obtained respectively. The starting pressure and operating pressure were taken as the evaluation of diffuser throat length Poor basis. Experimental data show that for this particular structure of the DF / HF lasers, the optimum length of diffuser throat is 17 times the equivalent diameter.