Backflow simulation and its influence analysis for gas generator of LRE

A 3D model of the generator and the gas flow inside the gas system while the engine is starting is established to eliminate the high-temperature phenomenon appearing at the head of LH_2/LOX engine gas generator as the engine starts.The inner flow field in the starting gas line was simulated and analysed after flow field calculation with the Fluent software.The calculation results of the steady flow field as the starter works for 0.65 s and the unsteady flow field in the range of 0～0.65 s show that the starting gas from the burned starter enters into the gas pipe by the declining gas intake, reflects on the inner wall,then goes into the gas generator and its head,and results in a over high temperature there.The numerical simulation of the steady flow field at 0.65 s was conducted.The result shows that the appropriate increase of the ablution flow and the gas intake angle(80°and 90°)is an effective measure to reduce the influence of the high temperature on the engine.