Aerodynamics of decelerators in nonuniform free-streams

Abstract

Conical decelerators traveling inside nonuniform far wakes are considered. Equations for pressure coefficients, static derivatives, and optimized drag body shapes have been theoretically derived and numerically solved. The methods used are based on Generalized Newtonian Theory. The drag coefficients and static stability derivatives have been evaluated at zero angle of attack. Results indicate that the misusage of a uniform velocity profile for nonuniform wakes may cause significant overestimation of pressure coefficients and drag coefficients. It was found that the nonuniformity of the wake velocity profile also affects the static stability derivatives and optimized drag body shapes. Moreover, the conical aerodynamic decelerator will be statically stable for semivertex angles of less than 45 degrees.