挤压式液体火箭发动机水击特性研究

以某四氧化二氮/偏二甲肼挤压式液体火箭发动机为研究对象,建立了包括液路动力学模型、充填动力学模型和气路动力学模型的发动机系统启动过程动态数学模型。仿真计算了发动机系统启动过程中不同节流孔位置和大小时的水击峰压。分析表明,在靠近阀门处设置节流孔可明显减小水击峰压,对氧化剂管路的作用较燃料管路更明显;较小的节流孔利于降低水击峰压,但尺寸须合适,否则会因推进剂流量下降而在节流孔处形成发射。

Study on Water Hammer Characteristics in Pressure-Fed Liquid Rocket Engine

While some N_2O_4/UDMH pressure-fed liquid rocket engine was served as study object,the numerical dynamic models including liquid line,line filling and gas line during the start-up process of the engine were established in this paper.The peak pressure of water hammer for various positions and size of orifice in the start-up was computed.The study showed that the water hammer would be lessened significantly when the orifice was set adjacent to the valve,and the reducing effect of oxidant line was larger than that of fuel line.The small diameter of the orifice was benefit to the pressure dropping of water hammer.Nevertheless,the size of the orifice should be suitable.Otherwise the injection at the orifice would be produced because of the flowrate reducing of the propellant.