Study on Failure Mechanism of Thrust Chamber Liner Wall under Complex Thermal Load
The liner wall of high-thrust hydrogen-oxygen rocket engine will crack in different degree after several tests,which will seriously affect the working reliability of the engine.In order to analyze the failure mechanism of thrust chamber wall under complex thermal load,according to the four stages of precooling-working-postcooling-relaxation involved in the actual working process,the stress and strain of the inner wall after single and multiple working cycles are calculated respectively,and the crack failure analysis and metallographic analysis are carried out for the inner wall material after decomposing.The results of simulation and material analysis show that the failure mechanism of the inner wall is that the residual tensile strain accumulates at the central point of the channel under the action of fatigue and ratchet,and the grain coarsening and recrystallization occur in the inner wall material at high temperature,which leads to the irreversible decline of the material properties,accelerates the failure of the structure and eventually produces cracks.