Nonlinear Aerodynamic Modeling and Analysis on Body of Fixed Canard Dual-Spin Projectiles

Considering that the aerodynamics of fixed canard dual-spin projectiles become very complex after adding the ballistic correction component, making it difficult to accurately describe the aerodynamic forces of the projectile body by the aerodynamic model of the original conventional rotating projectile, the nonlinear aerodynamics and modeling method on the body of this type of projectile are studied. Taking the interference effects from the canards and the forebody reversal into account, and using Fourier series to fit the periodic effect caused by the change of the forebody roll angle, an accurate aerodynamic calculation model on the body of fixed canard dual-spin projectiles is established in the projectile axis reference frame, which shows the relationship with the amplitude and phase of the generalized complex angle attack, the orientation of the forebody roll angle, and the structure of the original conventional rotating projectile from the principle. The CFD method is used to simulate and analyze the aerodynamics of the projectile body at different forebody roll angles and generalized complex attack angles. The results show that the aerodynamics on the body of fixed canard dual-spin projectiles exhibits strong nonlinear characteristics with the change of the generalized complex angle attack, and it’s not suitable to simply fit the trigonometric functions of the forebody roll angle. For the given incoming flows and forebody roll angles, the established model can accurately calculate the aerodynamic forces on the body of this type of projectile and the influences of the various factors, which can provide a basis for the in-depth study of its ballistic characteristics and the design of correction strategies.