Optimization design for the two-dimensional contour of the ramjet engine inlet

Taking the ramjet extended range projectile as the research subject, in order to improve the total pressure recovery coefficient, the parameter model and numerical simulation to the flow field of inlet have been assembled by the auto-optimization platform, simulated annealing technique has been used to optimize the cone angle of simple cone and double angle cone based on the highest total pressure recovery coefficient. After the optimization, the total pressure recovery coefficient of the inlet had been separately improved 10.2% and 5.1%. The numerical simulation results are better in accord with the test data, and they have the same error direction, it proved that the optimization results are believable. Four diffusion laws including equal divergence angle, equal area ratio, equal Mach number and equal pressure grad have been used separately to design the contour of the inlet expansion section, and the influence of the different diffusion laws to the inlet has been analyzed. The results show that the best angle cone can be found more efficiently through optimizing, and the inlet expansion section of the equal pressure grad has better flow field quality under design conditions.