Effects of Protuberance Size on Side Force Characteristics of Slender Body at Mach 0.7 and 1.3

Abstract

Protuberances on the surface of a space transportation vehicle affect the aerodynamic characteristics, particularly the side force. In this study, wind tunnel tests are performed under transonic conditions (0.7 ≦ M_∞ ≦ 1.3) on a slender body (of slenderness ratio 8.9) with protuberances of varied heights, width, or lengths. The corresponding computational fluid dynamics simulations are also conducted to aid understanding the flow physics and the aerodynamics. The results show that at Mach 0.7, the side force decreases due to the increase in the low-pressure region on the upper surface of the protuberance and also due to the change in the direction of flow around the protuberance. At Mach 1.3, however, the side force barely changes since a shock wave creates positive side force.