Numerical Analysis of Drag Reduction of Blunt Bodies with use of different Conical Spikes at Supersonic Speed

Abstract

Aerospace vehicles such as re-entry vehicles, missiles, rockets move at very greater speed with variations in properties around the flow pattern. Greater amount of heat and drag are associated with these vehicles. This mostly reduces the performance as well as damage can be caused to the important section of these aerospace vehicles. Different devices and structures have been designed and experiments have been conducted to study the effect of those structures in enhancing the performance of the vehicles. Different spikes, bleeding devoices, trailing flatters have been designed to reduce drag formed on aero-vehicles due to pressure, wave, skin friction factors. Mostly the shock waves created during supersonic flow and above are main reason to create the aerodynamic drag force on the bodies. The research carried out tends to computationally investigate the results related to f the aerodynamic coefficients on blunt body and blunt body with conical headed spike. A further tendency or curiosity to know about properties by replicating the flow conditions by dynamic modeling i.e by matching the Reynolds number and the mach number different total length to the diameter ratio 1,1.5,2 are investigated. As we know that the bodies move at different angles of attack hence angle of attack for them has been varied from 0 to 8o. from the solver we get different pressure forces, friction forces by using which we calculate the aerodynamic coefficients. In house developed solver by Zeus numerix has been used to compute the results by creating hybrid mesh i.e unstructured mesh. From the experimentally calculated results it is clear that the aerodynamic coefficients of drag have been nearly to a value of 0.80 for blunt bodies which have been achieved with less than 1% difference in computationally calculated results. Also from experimentally found out that spike with blunt conical tip has less amount of drag compared other spikes hence has been evaluated for computational purpose.