C/C复合材料喷管烧蚀壁面退移流固耦合仿真研究

In order to ensure the reliability of solid rocket motor C/C composites nozzle, a fluid structure coupling calculation model was established to accurately reflect the ablation process of solid rocket motor nozzle, so as to achieve high precision prediction of nozzle ablation rate. Based on the thermochemical ablation theory and the mass balance and energy balance relationship between the gas and the nozzle structure, a fluid structure coupling method for C/C composites nozzle considering wall retrogression is established and verified. The coupling among gas flow, heterogeneous chemical reaction and structure heat transfer is realized. The correctness of the model is verified by the calculation of nozzle ablation and the effects of aluminum content on the ablation rate are analyzed. The maximum relative error between the ablation rate of numerical simulation and the experimental value is 4.3%. Compared with the results of the coupling algorithm without considering the wall retrogression, the calculation accuracy can increase by 46%. The calculation results show that the ablation of C/C nozzle is the most serious near the throat. The increase of Al content in the propellant leads to the decrease of the concentration of oxidation components in the gas, thus reducing the ablation rate. These conclusions are consistent with the relevant research results of C/C nozzle ablation.