Design of Scramjet Nozzle Employing Streamline Tracing Technique

Abstract

A method for designing three-dimensional scramjet nozzles is presented, which employs streamline tracing based on flowfield of axisymmetric nozzle with optimum thrust. According to a typical hypersonic flight cond ition, an inviscid nozzle with rectangular entrance of 50mm×50mm, length of 560mm and height of exit 147mm is constructed and then the boundary layer correction is performed. Inviscid and viscous flowfields are computed in the design point by commercial software Fluent to get thrust and lift of the nozzle. Inviscid computational results show that, compared with a nozzle with straight walls, the nozzle designed by streamline tracing obtains an increase of thrust and lift by 2.7% and 69.5% respectively. Nomenclature C1 = constant along control surface DE C2 = constant along control surface DE FCE = thrust acting on the axisymmetric nozzle L = length of the nozzle Ma = Mach number of freestream Me = Mach number of exit point on the upper wall of axisymmetric nozzle Mj = Mach number of exhaust from combustor p = static pressure p0