Influence of the Transonic Crossing for Precision Ammunition

Although trajectography for small-calibre and long-range projectiles in particular, seem to be controlled since a long time, it is not totally mastered within transonic or even subsonic range. Given the high cost of the precision ammunition and the increasingly complex practical execution of the firing process due to the required distances, the use of Computational Fluid Dynamics is clearly an added value. However, since numerical simulations have very little value without a solid experimental basis, this study aims to establish the pillars for numerical modelling of these projectiles in the transonic domain. By means of studies carried out in the past and relatively new flow visualization techniques (Schlieren + Background Oriented Schlieren), the precise quantification of the drag as well as the various shocks propagating in the transonic domain were determined, with good agreement between all techniques.