Unsteady Aerodynamic Force Measurements of Sphere

Abstract

Magnetic force fluctuations acting on a sphere suspended in flow without any support interference with Magnetic Suspension and Balance System were measured. Two kinds of the fluctuations in drag direction were observed. They are 0.05 and 0.08 in Strouhal number. We observed that sphere drag reduced much suddenly for a short time at Reynolds numbers around critical one, and also observed that magnetic force perpendicular to drag acted on sphere rotationally near critical Reynolds number.