Research on the influence of two-dimensional inlet compression angles on inlet performance

The two-dimensional supersonic inlet is one of the most developed types of inlet. In order to explore the influence of such inlet geometric structure parameters on the inlet performance, an original inlet model was designed and based on this model, two geometric parameters, the primary compression angle $\theta_{1}$ and secondary compression angle $\theta_{2}$ were changed within a max range of $\pm 30 \%$. Then the computational fluid dynamics(CFD) method was used to simulate each group of changed inlet models in a standard operating condition of ground start. Two evaluation index parameters, the total pressure recovery coefficient σ and the static pressure rise π were applied to estimating the performance of the inlet. According to the CFD results, the influence of the two angles on the two evaluation index parameters were quite different, the $\theta_{1}$ had a monotonic influence on the static pressure rise and a non-monotonic influence on the total pressure recovery coefficient in the changing range. However, compared with $\theta_{1}$, the $\theta_{2}$ had a quite opposite influence on the two evaluation index parameters. Finally, an engineering supportive conclusion of the inlet theoretical design and a future researching direction were given.