Aerodynamic forces acting on a rotating circular cylinder in a uniform shear flow. (The case of relatively low-Renolds-number flow).

Abstract

Aerodynamic forces acting on a circular cylinder rotating about its axis in a uniform shear flow were numerically obtained at a relatively low Reynolds number. The range of the Reynolds number is from 20 to 100 while those of the specific circumferential speeds and the velocity gradients of the shear flow are from 0 to -2 and from -0.2 to 0.2, respectively. The following results were obtained : First, the mean lift coefficient C^-l is the sum of the lift due to the rotation of the cylinder (Magnus effect) and that due to the velocity gradient. Second, the mean drag coefficient is the sum of the profile drag on a cylinder standing still in a uniform flow and the Magnus drag due to the induced velocity by vorticity originating at the cylinder in rotation and by that of the shear flow in the wake.