$ Nozzle Mixing Chamber Experimental Three Groups Of Study

Tripropellant injector element is one of the most important components in tripropellant engine, which is widely researched. The cold flow injection test about tripropellant injector mixer is conducted in present paper. The experiment focuses on two aspects: discharge characteristics and atomization characteristics. Discharge coefficient is mainly researched in the discharge characteristic tests. And the mean size of the spraying droplet SMD and distributing index K are measured in the atomization characteristics tests.The injector experimental system is reconstructed and many injectors are designed and manufactured. The injectors varied with size or shape or other configuration parameters, including transition angle, recess length of internal and outer injector, mixer length, mixer width, the location of the orifice for gas, etc. The effects of configuration parameters and the gas pressure and the liquid pressure before injector on the discharge coefficient of two phase flux and the atomization characteristics are analyzed.Some conclusion can be drawn from the discharge characteristics experiment. First, thedischarge coefficient of two phase flux in the mixer depends on the ratio of gas mass to liquid mass. Second, the discharge coefficient of two phase flux increases with the decreasing of the mixer transition angle, the recess length of internal and outer injector, the mixer length, and the distance between the inlet orifice for gas and the mixer outlet. Although the pressure gradient is large at mixer outlet, the pressure changes little within mixer.The atomization characteristics experiment shows that the average diameter SMD depends on the ratio of gas mass to liquid mass , and the greater the ratio of gas mass to liquid mass .the less SMD. And the longer of the recess length and the mixer width, the lower of the atomization level. The length of mixer and the transition angle o also have influence on atomization level.