Experimental determination of the drag coefficient of conical penetrators and a penetrator with a flat front end during supersonic motion in sandy soil

Experimental studies were carried out to determine the coefficient of resistance when conical and cylindrical impactors penetrate into sandy soil. In experiments, the angle of half-solution of the conical tip of the penetrator varied from 10 to 90 deg. The speed of the penetrator changed in the range of 0.2–2.0 km/s. The average values of the drag coefficient are obtained for conical bodies with quasi-stationary supersonic motion in sandy soil with an average humidity of 7–12%, and for impactors with a flat front end - in sandy soil with a humidity of 0 to 16%. A significant dependence of the drag coefficient of thin cones ($\beta<$ 25$^\circ$) on the speed of movement and the absence of such a coefficient (taking into account the experimental error) for blunt cones and a flat-end striker is shown.