Drag Force, Drag Torque, and Magnus Force Coefficients of Rotating Spherical Particle Moving in Fluid

Abstract

The mutual influence of translational and rotational spherical particle movements in calm water was studied using experimental data and numerical simulation. Spherical balls with a density close to that of water were speeded up in special devices, which ensured the required ball rotational and translational velocity in the given plane. A video system was used to record the ball trajectory in water. The values of the drag force, Magnus force, and drag torque coefficients were determined experimentally and compared with the results of the numerical simulation of the particle motion. The evaluation of the experiments focused on the effects of two dimensionless parameters of the particle motion: the translational Reynolds number (or Reynolds number) and rotational Reynolds number. The experiments were carried out for the relatively slow (the dimensionless angular velocity Γ < 3.5) and relatively fast (5 < Г < 10) particle rotation. Relationships describing the abovementioned coefficients were developed, taking into account the mutual influence of the translational and rotational particle movements. It was found that the drag force and drag torque coefficients can be expressed as the functions of both the translational and rotational Reynolds numbers.