Aerodynamic Configuration Analysis of a Typical Inflatable Aerodynamic Decelerator

Abstract

A fore-body attached inflatable ballutes were considered for the aerodynamic analysis. Detailed CFD studies for sensitivity of aerodynamic coefficients to cone angle, varying payload length and center of gravity location were carried out. Flow simulations carried out for multiple angles of attack (AoA) at different altitude conditions. Variation of aerodynamic coefficients, i.e., axial force coefficient, normal force coefficient and pitching moment coefficient with angle of attack at multiple altitudes and free stream conditions is reported. Analysis for tumbling cases was carried out at higher altitudes. Aerodynamically, an IAD configuration, which is more stable and with maximum drag, i.e., with minimum ballistic coefficient is considered ideal. Based on the parametric studies, an optimum configuration was arrived, which was statically stable with (dCm/dα) at 0° of −0.18 and a ballistic coefficient of 4.6 which meets the mission requirements. Variation of pitching moment coefficient about stagnation point with angle of attack clearly indicates that IAD configuration is statically stable to 60° AoA.