A symmetry-based modeling of the angular dependence of aerodynamic forces on disk-shaped bodies

For disk-shaped bodies such as disk golf disks, the variation in aerodynamic force with the angle of attack is primarily governed by the angular dependence of the force component perpendicular to the disk face. By decomposing the total aerodynamic force into components aligned with the geometric symmetry of the disk, we obtain a simpler and more intuitive relationship with respect to the angle of attack. This formulation was validated through wind tunnel experiments conducted on disk golf disks. Our analysis also clarifies the origin of the nonlinear angular dependence of the drag coefficient and demonstrates that conventional approaches, being misaligned with the disk’s symmetry and failing to account explicitly for the resulting trigonometric relationships, lead to either over-parameterization or inaccuracies due to violations of trigonometric constraints.