弹射动力系统燃气发生器流热固耦合数值研究

In order to assess the working safety of gas generator in ejection power system, it is necessary to predict the mechanical response state of the gas generator shell in the working process. Based on software CFX and ANSYS, the fluid-thermal-solid coupling model of gas generator composite structure was established. The flow field and the temperature field in the gas generator were simulated by fluid-thermal coupling method, and the outer wall temperature was compared with the test data, then the simulated gas pressure and structural temperature distribution were imported into ANSYS to calculate the structural mechanical response. The simulation results show that, during the working process of the gas generator, the maximum temperature region of the straight tube section is located at the insulation layer clearance between the straight tube section and the rear head, and the maximum temperature region of the rear head is at the front end of mating surface of the head and throat liner.The maximum structural temperature is 354K, indicating fine insulation protection. The safety factors of stress in the main area of the straight barrel section and the rear head shell are greater than 3, meeting the design requirements, while the stress concentration exists in the outer wall near the circular corner transition of the flange, and the safety factor at the maximum stress region is 1.13, which indicates that the gas generator shell is in a safe state, but there is a risk of a significant reduction in safety margin.