A novel contour design technique of super/hypersonic nozzle diverging section with sharing throat

A straightforward technique has been developed to quickly determine the wall contour of super/hypersonic nozzles working at multiply Mach number which share a common throat section. Mach number distribution along the centerline of the nozzle is specified in advance and divided into two sections, both of which are described by the b-spline function. The first section is shared by different exit Mach number nozzles. The nozzle contour is determined by the method of characteristics plus boundary layer correction. An example of this design method is employed to illustrate the technique with a computational fluid dynamics calculation. The simulation results indicate that desired Mach numbers are obtained at the nozzle exit, and the good flow quality is attained for different nozzles within dMa/Ma<+/- 0.56% in the flow core region. This technique improves the design precision of the converging-diverging nozzle, cancels waves completely, and achieves nozzles with multiple Mach number exiting which share a common throat section.