Design Of Curved Shock Compression Surface And Experimental Investigation

To shorten the length of compression surface and assure the stability of the fore-body boundary layer on the surface, a new concept of curved compression ramp is proposed and a design method is investigated, with the method a curved shock forms. By using theoretical analysis, numerical simulation and wind tunnel testing, the characteristics of the curved compression ramp with different curvature, comparing with isentropic and conventional two-dimensional ramp compression, was introduced. The performance of the compression ramp are studied mostly at the design point and off-design point in the condition of uniform supersonic incoming flow, and slightly at the design point in the condition of non-uniform incoming flow. Curved compression ramp model with the designed Mach number 5.3 is processed. During the experiments at Mach number 5.3 and 3.85, the static pressure along the ramp and the total pressure at the exit section are measured and the schlieren photos of the curved shock are screened. The results indicate that the curved shock creator – curved compression ramp with small first compression angle can reduce the danger of the incoming boundary layer separation. Compared with the isentropic compression ramp the length of newly designed curved ramp can be reduced about 25 percent. The colligation characteristics are better than the other two in the different incoming flow and at different Mach numbers. Along the curved ramp an approximate constant pressure gradient is obtained, it is lower than the isentropic and much better than the two-dimensional plate ramps. The experiments results coincide better with the result of numerical simulation. All results point that the design method is feasible.