The Study On Mutilple Starts Of Pasty Propellant Rocket

Pasty propellant is a kind of new chemical rocket propellant with the advantages of solid propellant and liquid propellant. It has very extensive application prospects because it can realize thrust regulation and multi-time ignition that solid propellant couldn't, and also can overcome the disadvantages of liquid propellant's danger and engine structure's complexity. Multi-time ignition technology of pasty propellant rocket engine can not satisfy the long time interval requirement of flying vehicle's restarting in an armed state. It becomes the bottom-necks of restricting the development and application of pasty propellant. So it has a realistic meaning to investigate the multi-time ignition technology of pasty propellant rocket engine.With multi-time start of micro attitude-control pasty propellant rocket engine as its applied background, the related theoretic and experimental investigation of pasty propellant rocket engine multi-time ignition and flameout were carried out in this dissertation. Based on established burning flame spread model and flame quenching model of pasty propellant, ignition and flameout were numerically simulated and a lot of multi-time start experiments were simulated too. Primary design of pasty propellant rocket engine multi-time ignition and flameout system were finished on the basis of theoretical analysis and experiments. Research results lay a theoretic and experimental foundation for pasty propellant rocket engine multi-time start. In this dissertation, the main research contents include:(1)On the basis of thermal theory, mechanism analysis of pasty propellant multi-time ignition and multi-time flameout were done. According to the characteristics of strong instantaneous heat transfer, ignition model of pasty propellant was established under the conditions of plasma, and plasma ignition mechanism, physical chemistry process, ignition and flame spread process were investigated in detail.(2)Centering on the implementation of plasma ignition, Theoretic and experimental research on multi-time start of pasty propellant rocket engine were carried out. How to get composite plasma using the PWM technology was studied based on investigating the characteristics of plasma. Ignition system was developed according to ignition requirement of pasty propellant rocket engine. Fuzzy control and power implementation of ignition system were analyzed in detail based on ignition procedure. Through the application of plasma, ignition ability, first and multi-time ignition experiments of pasty propellant were performed, and furthermore the feasibility of multi-time ignition using the plasma technology was validated.(3)Flame spread model and flame quenching model of pasty propellant in the slender pipe were proposed on the basis of investigating flame heat transfer and flame quenching mechanism in slender pipe. System structure of multi-time flameout was studied and key elements of it were mainly discussed. The effect of spreading distance on burning rate, the effect of different channel size and different pressure on flame spread were simulated and analyzed numerically when the flame was spreading and quenching in the slender pipe. Enhanced cooling flame quenching experiments of different large plates and slender pipes were respectively carried out and the expected effect of flameout was achieved.Through systematic research of pasty propellant rocket engine multi-time ignition and multi-time flameout, the feasibility of pasty propellant rocket engine multi-time start was achieved from the theory and experiment. Research work in this dissertation has guiding significance for the design of pasty propellant rocket engine, and provides reference basis for pasty propellant striking from theory to application.