Study On The Coupled Calculation Of Combustion And Heat Transfer In LOX/Methane Rocket Engine

Thrust chamber is one of the most important component of the liquid rocket engine which works at bad working conditions.In order to avoid damage to the thrust chamber,studying of coupling heat transfer of chamber is very important.During the operation process,fuel combustion greatly affects the thermal load of chamber,so the numerical study of coupling combustion and heat transfer has great significance.Based on the hot firing test of LOX/Methane subscale engine,a coupled model simulation technology that working injection,combustion,flowing and heat transfer are coupled to one model in which muti-dimentional physical field simulation is done.In this paper coupled complete model simulation is applied to actual heat transfer process of liquid rocket engine to realize the heat transfer process and the effect of combustion on the distributing of thermal force,therefore,in return simulation technology of liquid rocket engine is improved further.The following is the contents of this work:1.Under the thought of coupled model simulation,a 2-D combustion model with real gas equation was built to simulate combustion among thrust chamber.The comparison of numerical results and experimental data shows that the deflection of thrust chamber pressure is 2.89%,the deflection of combustion efficiency is 3.08%.Simulating results agree well with the experimental data and indicate that the combustion model is efficient.2.Under the thought of calculate different areas and coupled on the interface,a 3-D heat transfer model with was built to calculate the governing equation of the coupled heat transfer progress.Make the heat flux that calculated by the combustion simulation as the boundary condition.Cycle 5 times until realize the computational convergence to simulate the injection/combustion/flowing/heat transfer coupled progress of thrust chamber.The comparison of numerical results and experimental data shows that the deflections of pressure drop in the throat channel and cylinder channel are 12.8% and 8.73%,the deflections of temperature rise of methane in the throat channel and cylinder channel are 11.78% and 9.41%.Simulating results agree well with the experimental data and indicate that the heat transfer model is efficient.3.In order to study the impact of chamber pressure on the combustion and heat transfer,make the mixing ratio of propellant is 6.37,calculate 3 working conditions of different chamber pressure: 5.53 MPa,7MPa,10 MPa.The computing results of combustion efficiency are 92.58%,94.43%,95.72%;The temperature rise of methane in the throat channel are 64.84 K,68.69 K,69.55K;The pressure drop in the throat channel are 3.181 MPa,3.289 MPa,3.326 MPa.Simulating results show that keep the mixing ratio of propellant constant,,the great pressure make the combustion efficiency higher and make the temperature rise and the pressure drop in the channel higher.While velocity of fired gas is almost unchanged.4.In order to study the impact of mixing ratio of propellant on the combustion and heat transfer,make the chamber pressure is 5.53 MPa,calculate 3 working conditions of different mixing ratio of propellant:6,6.37,7.The computing results of combustion efficiency are 91.89%,92.58%,92.93%;The temperature rise of methane in the throat channel are 62.48 K,64.84 K,68.07K;The pressure drop in the throat channel are 3.173 MPa,3.181 MPa,3.202 MPa.Simulating results show that keep the chamber pressure constant,the great mixing ratio of propellant make the combustion efficiency higher and make the temperature rise and the pressure drop in the channel higher.While the great the mixing ratio of propellant the smaller the velocity of fired gas.