Numerical analyses of re-entry module – apex cover separation aerodynamics at low subsonic mach number for various angles of attack

Abstract

Apex cover is one of the major subsystems of a crew module and its separation is one of the important aspects of any re-entry mission. Aerodynamic study of apex cover and crew module at the time of separation is a critical issue during the re-entry phase of the mission. These studies will give the details of various aerodynamic parameters which will be used for designing a collision free separation of apex cover from the crew module. During re-entry the crew module velocity varies from hypersonic Mach number in outer-inner atmosphere to supersonic, transonic and finally subsonic (high and low) Mach numbers till it touches down on earth. This separation event occurs when apex cover is separated from re-entry module before the deployment of drogue chutes. In this study re-entry module is considered as fore body and apex cover as aft-body. CFD studies have been carried out to estimate various aerodynamic coefficients of the apex cover at two different axial distances from crew module for various angles of attack (0‘, 45‘, 90‘, 135‘ and 180‘) using commercial software FLUENT. The turbulence model used in the study is SST K-ω. The effects of gap (axial distance between fore and aft bodies) and various angles of attack on aerodynamic coefficients like axial force, normal force and drag on fore and aft bodies, at low subsonic Mach number, is the subject of this paper.