Drag and Heat Flux Reduction on Hypersonic Re-entry Vehicles in Combination with Different Aerospikes

Abstract

Hypersonic re-entry space vehicles, reusable launch vehicles and intercontinental ballistic missiles all use a blunt body as its fore body to decelerate the re-entry vehicle with aerodynamic heating as the result. Blunt bodies produce more wave drag due to strong detached bow shock wave formation in front of the body. To overcome this, wave drag aerospike has been introduced in front of the blunt body. This aerospike weakens the strong detached bow shock into a weaker oblique shock. It also creates a re-circulation zone (due to the adverse pressure gradient) in front of the body which greatly reduces the high pressure on the front portion of the body. Hence, aerospike is used in front of the blunt body to reduce the wave drag. This aerospike concept was first conceived in the 1950s as a means of reducing the heat transfer rates and aerodynamic drag on axis-symmetric blunt bodies. Many researchers have carried experiments out on the aerospike concept. In this study, computational investigations were carried out on blunt bodies with and without spikes, to know the flow behaviour at different Mach numbers with the help of computational fluid dynamics software. Experimental validations were compared. The effects on the coefficient of drag due to changing the spike tips, such as different aerospikes and spikes, were studied. The effect of the heat flux of the spike was also studied. Finally, conclusions on the optimum tip portion spike were chosen.