Ablation Analysis and Simulation Study of a Liquid Oxygen–Kerosene Gas Generator

This study addresses the ablation issue observed in the injection panels of a ring-shaped liquid oxygen and kerosene gas generator during thermal testing. A combined approach of experimental analysis and numerical simulation was employed to systematically investigate the ablation mechanism and influencing factors. The research focuses on a ring-shaped gas generator featuring an array of eight pintle injectors. Scanning electron microscopy (SEM) was used to characterize the microstructure and composition of the eroded regions, while numerical simulations based on the Navier–Stokes equations and the discrete phase model were applied to uncover the core ablation mechanisms. Experimental results show that ablation is primarily concentrated at the 45°, 135°, 225°, and 315° orientations of the pintle injectors, which closely align with regions of high oxygen atomic mass fraction in the simulations. SEM analysis reveals a significant increase in oxygen atomic content (up to 14.36% and 20.35%) in the severely eroded specimens, accompanied by oxidation products of metals such as Cr, Fe, and Ni (e.g., Cr2O3 and FeO), indicating that the synergistic effect of an oxygen-rich environment and high temperature leads to the spallation of the oxide layer on the GH4169 alloy surface. Further findings suggest that the degree of ablation is linked to the uneven flow distribution caused by gravity, with more severe ablation occurring at the three injectors located downstream of gravity among the eight injectors due to the concentration of propellant flow. Additionally, comparisons between simulation and experimental data indicate that the main flame in the multipintle injector array is located at the center of two adjacent pins. The research outcomes have significant engineering implications for improving the reliability and lifespan of ATREX engines.