LAUSR

Use of spike on a hemispherical body changes the flow field and hence the aerodynamic drag. Computational studies have been made to obtain the flow field around a hemispherical body with spikes at a hypersonic Mach number of 6. The effect of shape of spike tip and length has been studied. Laminar computations have been made adopting structured grid using commercial software Fluent. It is observed that use of a sharp spike itself reduces the drag signicantly. However the use of a hemispherical head spike further reduces the drag. Contribution of dierent components towards drag indicate that the increase in length of a spike do not change the spike contribution. However the flow field on main body is altered which leads to reduction in dragwith change in length. Estimated maximum drag obtained is found to be highest in comparison to any reported drag value in literatures with any spike shape and length.