Probase: a Software Application to Estimate Drag in Base Bleed Technology Units using Large Eddy Simulation

Abstract

Base Bleed is a widely used technology to reduce the drag of bodies in flight such as in the case artillery projectiles. It is based on increasing the pressure at the rear of the body through the injection of a low velocity fluid. In this paper we present a new PC application called “PROBASE†developed by EXPAL Systems SA and the Technical University of Cartagena (UPCT). The application, based on Qt® and OpenFOAM® and with a user friendly “interfaceâ€, is able to estimate drag coefficients of slender bodies with Base Bleed units. This estimation is performed through the simulation of flight conditions and the resolution of the Navier-Stokes equations of the flow field with AUSM schemes and Large Eddy Simulation turbulence models. In the presented version, the transient computations are done with an axisymmetric two-dimensional approach of the problem, zero angle of attack and a fixed Base Bleed mass flow rate and swirl. Validation against experimental data is also included.