Effect Of Spillage Slot's Entry Angle On The Performance Of 2-Dimensional Hypersonic Inlet

Ramjet engine, the most attractive power device used in high supersonic aircraft, is now one of the most popular engines studied by researchers all over the world. As the ramjet decreases the flow's speed and increased the pressure by its own structure of inlet, it has no compressor and turbine in it, which makes the structure of the engine simpler, lighter and smaller. Compared to the inlets of other ramjet engines, 2-dimensional hypersonic inlet is relatively simple and clear in its structure. So it is convenient to use 2-dimensional hypersonic inlet to analysis problems. And it is easy in engineering application. But it also exists some disadvantages. The main problems are that when the inlet flies in low designing Mach number, the aerodynamic performance is so different from that in flying in designing Mach number, and that when flying in the same condition, the total pressure recovery coefficient is worse than that of other inlets.To improve these two problems, this paper bases on researches in high supersonic inlet and uses simulation to study the flow in 2-dimensional hypersonic inlet. This paper also verifies the effectiveness of simulation by examples. It proves that simulation used in this paper can describe the flow of 2-dimensional hypersonic inlet. Then this paper analyses the aerodynamic performance of 2-dimensional hypersonic inlet with and without spillage slot in condition of low Mach number. It proves that inlet with spillage slot has a better total pressure recovery coefficient than the one without spillage slot. In the last, the geometry characteristic of inlet angle is researched in this paper. Firstly studying respectively on the entry front angle and the entry back angle that are processed smoothly and keeping the other conditions unchanged, analysis the effects to the performance of 2-dimensional hypersonic inlet below the design Mach number. Finally the entry front angle and the entry back angle are processed smoothly at the same time and keep the other conditions unchanged, analysis the effects to the performance of 2-dimensional hypersonic inlet below the design Mach number. Results show that the smooth processing of the entry front angle can reduce the drag coefficient of 2-dimensional hypersonic inlet and improve the performance; the smooth processing of the entry back angle just increases the drag coefficient and can not improve the performance; the smooth processing of the entry front angle and the entry back angle at the same time also can not improve the performance of 2-dimensional hypersonic inlet.