Fluid Dynamics

, Volume 44, Issue 1, pp 141-157

First online:

Aerodynamic coefficients of a spinning sphere in a rarefied-gas flow

  • A. N. Volkov

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access


A three-dimensional rarefied-gas flow past a spinning sphere in the transitional and near-continuum flow regimes is studied numerically. The rarefaction and compressibility effects on the lateral (Magnus) force and the aerodynamic torque exerted on the sphere are investigated for the first time. The coefficients of the drag force, the Magnus force, and the aerodynamic torque are found for Mach numbers ranging from 0.1 to 2 and Knudsen numbers ranging from 0.05 to 20. In the transitional regime, at a certain Knudsen number depending on the Mach number the Magnus force direction changes. This change is attributable to the increase in the role of normal stresses and the decrease in the contribution of the shear stresses to the Magnus force with decrease in the Knudsen number. A semi-empirical formula for the calculation of the Magnus force coefficient in the transitional flow regime is proposed.


spinning sphere transitional flow regime drag force coefficient Magnus force aerodynamic torque coefficient