Prediction of drag coefficient of a base bleed artillery projectile at supersonic mach number

Abstract

An artillery projectile in flight produces aerodynamic drag in base region known as base drag. By injecting hot gases into the base region at low speed, base drag can be reduced. The reduction in base drag significantly increases the range of the projectile. In the present work. Numerical simulations over 155 mm artillery projectiles are performed with and without base bleed. The free stream Mach number is 2.26. Simulations are performed with commercial CFD package, ANSYS-FLUENT. The numerical method is based on density-based algorithm and K-? SST turbulence model was chosen for calculation of turbulent stresses. Computations are performed for Angle of Attack (AOA) for 0° and 10°. The predicted drag coefficient for AOA=0° is validated with experimental data. The hot gases are injected at a Mach number and pressure of 2.26 and 101325 respectively. With the base bleed, 14.4% reduction in drag coefficient for AOA=0° is observed. The effect of base bleed on flow field and surface pressure is analyzed and presented in the paper.