Author(s)

S. Abdolahi & M. Ebrahimi

Abstract

In this research, an investigation into the aerodynamic characteristics of a body with deployable drag surfaces for recovery system has been carried out using computational fluid dynamics. Two models of the body with retracted position of drag surfaces and deployed position of drag surfaces has been considered for studying the influence of drag surfaces on the flow structure and aerodynamic forces. For this purpose force measurement and flow visualization for each case has been carried out in Mach numbers 0.4 and 1.5. Validation of the results has been done through comparing aerodynamic coefficients with results of a semiexperimental method. A general study of the main aerodynamic coefficients shows that at all angles of attack, the coefficient of lift decreases and the coefficient of drag increases. Visualization of the flow structure shows a region of separated flow upstream and a dead flow region with large vortices downstream of the drag surfaces. Keywords: numerical simulation, aerodynamic characteristics, recovery system, drags coefficient, pressure distribution, shock wave, vortex. 1 Introduction Several methods have been employed for recovery of flying objects with various degrees of success. But the most prominent method, especially for heavier bodies is parachute recovery [1], in which a number of parachutes are deployed in a predefined sequence to reduce the body’s rate of descent. Physics of supersonic flow around parachutes has its own complexities such as area oscillation and shock wave formation [2]. The controlled deceleration of a flying body is a vital part of many aerospace missions that involves significant technological challenges and creative engineering solutions [3]. For many flying objects,

Keywords

numerical simulation, aerodynamic characteristics, recovery system, drags coefficient, pressure distribution, shock wave, vortex