Computation of Drag of a Ballistic Reentry Body at Various Mach Numbers

摘要

It is necessary to dissipate the kinetic and potential energy of a reentry object from Earth orbit and recover it on the ground with small impact point dispersion without exceeding thermal and structural limits. This can be accomplished either through aerodynamics or propulsion or both. The entry can be ballistic, semi-ballistic or lifting entry. In a non-propulsive ballistic entry, drag is the important aerodynamic parameter that influences the trajectory design other than the mass and entry flight path angle. While re-entering into the atmosphere, deceleration is very high because of Earth gravitational force, to reduce the deceleration rate drag of the configuration should be very high. To increase the drag reentry configuration has to be blunt. In this paper, the flow field around a typical ballistic reentry body has been investigated using RANS CFD simulations. Ansys-Fluent, CFD++ with Spalart-Allmaras and realizable k-ε turbulence models have been used in the present analysis. In this paper, various drag properties for a spherically blunt cone flare configuration, code-to-code comparison of drag and Cp distribution on the body have been discussed for various Mach numbers.