Aerodynamic characteristics of an ogive-nose spinning projectile

This work experimentally investigates the Robins-Magnus effect on a 5-caliber spinning projectile at a low subsonic Mach number of 0.1 corresponding to a Reynolds number of 3.2 x 10(5) based on the model length. The model configuration tested was a cylinder with spherically blunt tangent ogive nose portion. The normal, axial and side force coefficients were obtained for various angles of attack (alpha) ranging from 0 degrees to 34 degrees with non-dimensional spin rates (Omega) of 0-0.05. Results indicate that the side force coefficient increases with a up to a value of around 28 degrees and decreases thereafter. Interestingly, in the range of spin rates considered in the present study, normal and axial force coefficients are not affected due to spin. However, the side force coefficients are seen to increase with spin rates at higher a. Flow visualization studies are demonstrated to explain the underlying mechanism behind the variation of these aerodynamic coefficients.