Research An Ignition Process Of Paste Propellant Gas Generator

Paste propellant gas generator is a new adjustable gas generator,combines the advantages of liquid rocket and solid rocket,which has the characteristics of simple structure,multiple starts,adjustable thrust,highly safety and highly reliability is a very broad application gas generator.This thesis studies the ignition process of paste propellant gas generator based on the multiple starts gas generator.The main research work of this thesis includes:(1)The constitutive equation of three kinds of paste propellants were determined by the straight pipeline flow experiment.In the determination of the constitutive equation,the Bagley correction method was introduced to obtain the modified parameters to refit the constitutive equation and reduce the experimental error.The modified Bagley method was used to reduce the error of the constitutive equation with an error 3%?12%to less than 2%.According to the obtained power law,the curve of the constitutive equation was in good agreement with the experimental data and the results show that the Bagley error correction method has a good effect.It improves the accuracy of the equation.(2)Three constitutive equations of paste propellants were used to simulate the flowing state in the gas generator.The simulation in different pressure,gives the pressure distribution and the flow distribution in the gas generator.The results show 3#paste propellant flow better;cylindrical circular pipe flow with the characteristics of flat flow;the position of internal flow velocity maximum point is the one-way flow control valve outlet straight section.This has some reference significance for analyzing the working status of the paste propellant gas generator,handling the problems of the gas generator and improving the design of the scheme.(3)The heat transfer simulation of hot restart was carried out to compare 45#steel,nickel alloy and tungsten copper as the heat transfer part.The results show that combustion chamber working less than 20 seconds,the gas generator temperature is safe,and it is not affected by the reverse heat transfer;it can be restarted for a period of time after working no more than 20 seconds;tungsten copper,with large thermal conductivity,anti-ablation property,selected as the best heat transfer member materials,and the simulation result is the best;the working conditions and the effect of the thermal protection relation with the actual environmental conditions.(4)The paste propellant heat test was done to get ignition temperature,get pictures of the test process change image.A pasty propellant gas generator was designed and a relatively complete start-up test was finished with it,including the determination of average flow rate of the gas generator,single and repeated start test.The results show that paste propellant ignition point is about 220 ?;the key parts of the paste propellant gas generator has enough safety strength;the paste gas generator has a good single and repeated start-up effect.At the beginning of the start-up,combustion oscillation was found in combustion chamber during the matching process of burning rate and combustion chamber pressure.The bubble in the pasty propellant caused a certain pressure fluctuation on the internal trajectory and the pasty propellant rheological characteristics were affected by the heat transfer.The work of this thesis is focus on the ignition process of paste propellant gas generator which provides some theoretical research ideas and practical reference for the design of paste propellant gas generator and its further research on hot start performance.