EXTENDED RANGE OF 155mm PROJECTILE USING AN IMPROVISED BASE BLEED UNIT: SIMULATIONS AND EVALUATION

摘要

Numerical tools were applied to the prediction of the performance of the 155mm Heer artillery shell, both in terms of projectile drag without base-bleed and the drag reduction with such a device. The predicted drag from STAK-CCM+ and the in-house code CFDnFlow compared well with firing data at supersonic speeds. Base-drag reduction using base bleed was predicted in a consistent manner with the DES model, although some variation in data was observed. Trajectory simulations at two elevations using the CFD results compared well with firing data. Using the CFD tools the shape of the base was modified to achieve better pressure recovery. For example the introduction of a cavity in the base reduced base drag by 25% for mass injection parameters up to 0.006.