Starting characteristic of double-nozzle model in directly drained CW DF/HF chemical lasers

To study the starting characteristic of directly drained CW DF/HF chemical laser(DDCL), a double-nozzle small-scale device of DDCL gas channel was set up, and a series of experiments were conducted with different stagnation pressure of secondary flow. The effect of stagnation pressure in secondary flow on the starting characteristic was studied, and the experimental results show that greater stagnation pressure of secondary flow results in lower starting pressure of experimental device, the starting pressure without secondary flow is obviously higher than that with secondary flow, thus it is helpful to start DDCL with combustor flow. An theoretical model from the entrance of nozzles to the exit of diffuser is constructed by using one-dimension method. The change law of the starting pressur