EFFECT OF BODY SHAPE ON THE AERODYNAMICS OF PROJECTILES AT SUPERSONIC SPEEDS

An investigation has been made to predict the effects of forebody and afterbody shapes on the aerodynamic characteristics of several projectile bodies at supersonic speeds using analytical methods combined with semi-empirical design curves. The considered projectile bodies had a length-to-diameter ratio of 6.67 and included three variations of forebody shape and three variations of afterbody shape. The results, which are verified by comparison with available experimental data, indicated that the lowest drag was achieved with a cone-cylinder at the considered Mach number range. It is also shown that the drag can be reduced by boattailing the afterbody. The centre-of-pressure assumed a slightly rearward location for the ogive-cylinder configuration when compared to the configuration with boattailed afterbody where it was the most forward. With the exception of the boattailed afterbody, all the bodies indicated inherent static stability above Mach number 2 for a centre-of-gravity location at about 40% from the body nose.