关键词: 火箭推进剂喷嘴;可调推力火箭发动机;静态特性;瞬态响应特性

Abstract: The flow positioned injector can ensure invariant injecting speed and gives high combustion performance for variable thrust liquid propellant rocket engines.Static and dynamic mathematical models of the injector are developed.Basic design rules to ensure invariant injection pressure drop are deduced from the static model. For an ideal injector, that is, the flow coefficients are constant, a invariant injecting speed can be realized accurately through selecting a adequate spring rigidity. While in the practical situation, the effects of the flow coefficients variation on the injecting speed must be compensated by a special structure design.Based on the dynamic model, transient response of the injector is analyzed via digital simulation method.The results show that the injector can maintain almost constant injecting speed during transient process if the injector has a adequate dynamic resistant coefficient.

Key words: Rocket propellant injector;Controllable thrust rocket engine;Static characteristic;Transient response characteristic