超音速分离线喷管大摆角状态下化学烧蚀动态仿真OA北大核心CSTPCD

Aiming at the wall regression caused by chemical ablation in the supersonic split line nozzle with large deflection an-gle,a corresponding dynamic simulation model has been established based on the dynamic mesh technology,which realize prediction of the nozzle chemical ablation rate under different combustion chamber conditions.The throat ablation rate of 0.048 6 mm/s was ob-tained by means of the preliminary steady-state calculation,5.67%higher than the experimental result,verifying reasonableness of simulation setup.Then the state result was used as the initial field of transient calculation to carry out the corresponding dynamic simulation calculation of nozzle's chemical ablation.The vector angular amplification factor of the nozzle is reduced by 0.42%in 0.5 s simulation time due to the wall regression,and the most serious ablation position of nozzle is near the split line structure on the lower sidewall of the symmetry plane due to the obstruction of the gas flow,and the maximum ablation rate is 0.074 5 mm/s.Increas-ing the combustion chamber pressure or temperature will lead to a decrease in the ratio of ablation rate between the back and front sidewall of split line at the same circumferential position.For the less varied profile near the split line,this ratio is decreased by a-bout 10%with the increase of combustion chamber pressure from 5.5 MPa to 7.5 MPa and by about 15%with the increase of tem-perature from 3200 K to 3600 K.