An axisymmetric supersonic nozzle computational flow analysis for a ground test facility

An axisymmetric convergent-divergent nozzle of Mach 5 for a high-speed ground test facility is computationally investigated in this study. CD nozzle profile design process was initiated by generating an inviscid contour of the nozzle and its performance was studied using CFD simulations by monitoring of velocity and Mach number distribution along the nozzle centre-line. Later, in order to determine flow viscous effects, viscous CFD simulations of the same profile is performed to gauge the boundary layer thickness growth along the length of the nozzle. Based on the maximum boundary layer thickness of the nozzle exit, the nozzle contour is adjusted to achieve the design Mach number at a given pressure ratio. Further, specific to its ground application usage, nozzle length optimization was performed based on a criteria of optimal flow parameters comparison at the nozzle exit plane. CFD results of the redesigned and optimized nozzle contour depicts good flow quality in the core flow region, where Mach number variation is found to be less than 0.5%, total temperature <1% and total pressure variation <0.5% with indirect benefits in reduction of its mass and material cost.