Coupling Impacts of the Spanwise Shear Flow and the End Effects on the Magnus Effect for a Cylinder with Two Free Ends

The coupled effects of the spanwise shear flow and the free ends on the Magnus effect of a finite cylinder were investigated in this paper. Large eddy simulations were conducted, maintaining a Reynolds number of 4.6×104 and a constant aspect ratio of 10. The spin ratio ranged from 0 to 3, and the dimensionless shear parameter ( ) ranged from 0 to 0.06. As the spanwise shear flow passed over the rotating cylinder, the wake vortices were oriented obliquely in the direction of the increasing incoming velocity. The rotation effect at the end of the cylinder exhibited lower incoming velocity increases, whereas it decreased at the other end, resulting in asynchronous flow. As increased from 0 to 0.06, the periodic shedding of the wake vortices decreased, exhibiting multi-frequency shedding, with the spin ratio at the onset of this phenomenon decreasing from 1 to 0.5. The results indicate that, within the studied parameter ranges, an increase in elevates the drag coefficient without affecting the variation trend of the drag coefficient with regard to the spin ratio, while the lift coefficient decreases. As the rotation effect intensified, the impacts of the spanwise shear flow and the end effects on the aerodynamic coefficients became increasingly pronounced.