Numerical Simulation And Performance Analysis Of Scramjet Inlets

With the progress of the research and application of modern aerospace technology, the development of hypersonic vehicles has been pushed to a new climax. Scramjet inlet is of great importance in the hypersonic airbreathing propulsion system and plays significant role in the realization of hypersonic flight.Full 3-dimensinal N-S equations are solved by using finite volume method, second-order Harten-TVD spatial scheme, and algebraic Baldwin-Lomax turbulence model. In order to solve the complicated supersonic/hypersonic turbulence viscous flow field, a program for steady flow is built by using implicit LU-SGS method.The code calibration is completed by comparing the numerical results with data from two experiments, one of which is test of a 2-D hypersonic inlet with internal compression and the other a sidewall compression inlet. Good agreement of numerical and experimental results proves the possibility and credibility of the numerical method. 2-D, axisymmetric, and sidewall compression scramjet inlets flow fields are calculated and the performance of each inlet is analyzed.Configurations of generic sidewall compression scramjet inlets are introduced and two kinds of spillage are introduced respectively. Spillage induced by the back-swept leading edge of sidewall is called Configuration Spillage, while spillage evoked by the pressure difference is described as Pressure-Driven Spillage. A parametric analysis of the inviscid effects of leading edge sweep, sidewall compression, width-height ratio, cowl position and inflow Mach number on spillage is finished. Numerical simulations are completed for a series of inlets at various flight height and velocity. The research indicates that the area of spillage window, which is mainly determined by the position of the cowl, significantly influences the spillage characteristic of the scramjet inlet.