**Abstract**

The numerical simulations over several reentry vehicles are carried out by solving time-dependent compressible laminar axisymmetric Navier-Stokes equations for Mach 1.2–6.0. The fluid dynamics equations are discretized in spatial coordinates using integral formulation in conjunction with a finite volume method which reduce to semi-discretized ordinary differential equations. A local time-step is used to achieve steady-state solution. The numerical computation is carried out on a single-block structured computational grid. The flowfield features over the reentry vehicle such as formation of a bow shock wave ahead of the fore-body, expansion fan on the shoulder, and recirculation zone in the base region are well captured in the numerical simulations. Lower pressure acting on the base of the reentry capsule acts as base drag. The base drag coefficient based on maximum cross-section of the reentry capsule must satisfy inequality. The base drag coefficient is a function of several geometrical parameters of the fore-body and back-shell of reentry capsule, boundary layer, formation of free-shear layer in the wake region and freestream Mach number. The purpose of this chapter is to numerically evaluate and tabulate the base pressure and the base drag coefficients of various reentry space capsules at zero angle of incidence.

**Keywords:** aerodynamic, base drag, CFD, high speed flow, viscous flow, reentry vehicle, shock wave
