前直段长度对回流脉冲爆震燃烧室起爆特性影响研究

A numerical simulation model was developed and experimentally validated for the detonation characteristics of the reverse flow pulse detonation combustion chamber of a pulse detonation turbine engine （PDTE），and the effects of different reverse flow pulse detonation combustion chamber front straight section lengths on detonation wave generation were compared and analyzed using the calibrated model. The results show that the simulation model and method established in this paper can correctly predict the propagation process of detonation combustion in the reverse flow detonation combustion chamber under test conditions，and the numeri⁃ cal simulation results show that when the length of the front straight section is less than 4 times the diameter of the tube，the high-temperature region in the bending tube is separated from the high-pressure region，and the com⁃ bustion wave does not turn into the shock wave. When the front straight section is greater than 6 times the diame⁃ ter of the tube，with the front straight section longer，the location of the generation of detonate waves closer to the exit of the bend，but the total detonation distance increases. In the design of the reverse flow pulse detonation combustion chamber，increasing the length of the front straight section could shorten the axial distance between the compressor and turbine，but it will increase the total length of the detonation chamber.