Numerical Solution Of Liquid Hydrogen/Oxygen Rocket Thrust Chamber Structure Failure

The present study is focused on the regenerative cooling rocket thrust chamberusing liquid oxygen (LOX) and hydrogen (LH2) as propellant, with its advantages inperformance, adaptability, reliability and economy became the launch vehicle’s mainpower plant. The thrust chamber is important component in the aerospace propulsionsystem for propellant combustion and providing power for rocket launch. Because ofits complex structure and strict working situations there are security risks for reuse.Therefore, it is of great significance to the study of the thrust chamber.During the launch, the thrust chamber is operated by high pressure propellantcombustion, and the regenerative cooling technique introduces an enormoustemperature gradient between the inner of the thrust chamber wall and the coolingchannel. It is probably to cause the wall creep, and even lead to wall rupture.The main topic of the present study is the numerical solution of thrust chamberwall failure problem. Three-dimensional effects are considered. The contents are asfollows:(1) The numerical simulation of the temperature field of the regenerative coolingrocket thrust chamber will be presented. The main purpose is to get the temperaturedistribution and pressure distribution of the thrust chamber wall, including thefollowing two parts.①Thermal analysis of the combustion gas is the foundation. In order to separatethe hot gas field as single computational model the influences of the other physicalsystems have to be taken into account by boundary conditions. The gas propertieschanges with temperature and pressure are considered. Both, the standard k-εturbulence model and discrete ordinates radiation model (DO) are used incombination in order to describe the transonic flow with heat transfer of hot gas. Afterthe calculation is complete, the local Mach number, temperature and pressuredistribution in the axial direction of the near-wall hot gas are obtained and the resultsare operated by the method of polynomial fitting.②Thermal fluid-structure interaction analysis of thrust chamber cooling channelis the next. The structure model is composed of the half of the cooling channel andcooling liquid as well as the corresponding boundary conditions given by the heattransfer and pressure. Operations of the fluid and metal properties are the samemethod with the hot gas. The convection heat transfer coefficient in the hot-gasboundary is calculated by Bartz formula, and the radiation heat transfer is describedby the uniform composition of the hot gas on the wall radiation heat flux formula. Theparameters of both formulas are determined by the previous fitting polynomials. The above simulation obtains the temperature and pressure distribution of the thrustchamber wall.(2) In order to get the wall failure results the creep analysis is the last calculation.The previous temperature and pressure distribution of chamber wall have to be takeninto account by boundary condition. The creep strain rate is determined by Dornequation related to load and temperature. The equivalent creep strain and the locationof the maximum creep strain will be obtained.By the above calculations, the conclusions will be discussed in the following.(1) The maximum temperature and heat flux of the wall both occur in the throatregion.(2) The maximum creep strain also occurs in the throat region.(3) Under the combined effects of temperature and pressure, the throat regionappears creep plastic deformation. With time, the deformation will gradually increase.Thrust chamber is one of the rocket recyclable components. Not only the designand manufacture of the thrust chamber, as well as its future reuse research, thepresented study has some reference value.