Flight Behaviors of a Complex Projectile using a Coupled CFD-based Simulation Technique: Free Motion

摘要

This paper describes a computational study to understand the free roll, pitch, and yaw motion of a canard-controlled, fin-stabilized projectile. Numerical computations were performed for this projectile using an advanced coupled computational fluid dynamics and rigid body dynamics technique. Additionally, the coupled approach was tailored to be constraints-based for the rigid body dynamics allowing for pure pitching and pure rolling motions to be studied prior to considering the full roll-pitch-yaw. Flow visualizations and aerodynamic force and moment computations indicate unsteady canard stall at high angle of attack and significant interaction of these canard vortices on the afterbody-fins. Parameter estimation was performed to obtain aerodynamic coefficients, assess the aerodynamic model, and understand the roll-pitch-yaw coupling. These results suggest that improvements to aerodynamic modeling are necessary to better capture high angle of attack phenomenon such as unsteady canard stall and vortex interactions. Analysis of the pure pitch and pure roll predicts the coupled roll-pitch-yaw motion well with the exception of unsteady and interaction effects during periods of high angle of attack.