EFFECT OF ROTATING TAIL ON THE AERODYNAMICS OF GUIDED ARTILLERY SHELL

Abstract

Guided artillery shells use aerodynamic control force generated by canards in order to maneuver the shell. Due to low aspect ratio of the guided shells, the flow over the tail fins is affected due to canard deflections (See Figure-1). Freely rotating tail is used in guided shells in order to avoid the adverse rolling moment. Rotation of tail fin plays a crucial role in the aerodynamics of the artillery shell. In the current study, effect of rotation rates of tail fin on various aerodynamic coefficients is studied using computational fluid dynamics (CFD). The maximum tail fin rotation rate is estimated by using unsteady CFD simulation. The rotation of the tail fin is simulated by employing overset mesh and 1 DOF model in ANSYS Fluent CFD Software. Various aerodynamic coefficients are estimated for canard control deflection with tail rotation rate varying from 0 to maximum value. Aerodynamic coefficients show a significant change with reference to non-rotating tail simulation. However, for the rotating tail simulations the tail rotation rate has very minor effect on the aerodynamic coefficients.