Design Method, Numerical Simulation And Experimental Research Of Hypersonic Inlet

The design method,performance varying with parameters and some problems existing in ground test of hypersonic inlets were researched by using the method of numerical simulation and ground test.Based on summing-up of the existent design method of two-dimensional and three-dimensional inlets,a parametric design method of two-dimensional hypersonic inlet was established by analyzing the restrictiveness and sensitivity of the geometric parameter of the inlet.It is indicated that,by adjusting the parameters which were chosen in the design method, the inlet performance would be affected sensitively and the inlet with distinct configuration could be designed,and the optimization design about hypersonic inlet would become easier by using this method.The inlet performance varying with geometric or flow parameters were studied detailedly by using numerical simulation and ground wind tunnel test.It is indicated that the total pressure recovery,pressure diffusing and mass flow capture capability are influenced by the first wedge angle and the total turning angle of the forebody distinctly.Also,the total pressure recovery and the starting characteristics are influenced by the first wedge angle of the cowl and the inner contractive ratio of the inlet.Two different spillage ways were defined by analyzing the flow field structure of the sidewall compression inlet.It is indicated that the spillage caused by pressure gradient is very important.Effect of the boundary-layer states on the inlet performance was researched using numerical simulation method.Forced boundary-layer transition of an inlet was conducted in hypersonic gun tunnel to prove the important effects on reducing separation and improving inlet performance of turbulence boundary-layer.The results indicate that it is important to examine the boundary layer states when the test program is planned,and it should be considered seriously whether the boundary layer of the inlet is turbulence or not before the experimental data is analyzed or adopted.The starting process of hypersonic inlet in impulsive wind tunnel was investigated by using numerical simulation method.The mechanism of inlet starting characteristics influenced by the initial plenum pressure of the tunnel was revealed.It is indicated that inlet starting is promoted by a decrease in initial cabin pressure of the tunnel.Whether the inlet can start or not is sensitive to the initial cabin pressure when the inlet contractive ratio is relatively large.A source term method was developed to simulate the flow field of inlet coupled with combustion chamber,and parallel computing was used to accelerate computing speed.The results indicate that this method is an effective analytic tool for researching the interaction between inlet and combustion chamber and integrated designing of hypersonic vehicle.