Numerical Investigation of Slip Effects on the Three Dimensional Flow Past an Impenetrable Rotating Spherical Nano Particle

چکیده مقاله

The drag and lift forces acting on a rotating impenetrable spherical suspended particle in a uniform flow are numerically studied by means of three-dimensional numerical simulation with slip boundary condition at Reynolds numbers in the range of 0.1 < Re < 100. The tangential shear stress is assumed to be proportional to slip velocity at the boundary. A single dimensionless parameter, the so-called Trostel number (Tr), is defined to account for the slip at the boundary of the sphere. Increasing rotation and slip changes the flow patterns around the spherical particle. Increasing slip decreases the effects of rotation on the flow patterns around the rotating sphere. Rotation increases the drag and lift force exerted by flow at the surface of sphere but the values of drag and lift coefficients decrease by increasing slip. At full slip condition, rotation of the sphere has no significant effects on the drag coefficient values; moreover the lift coefficient of flow around the rotating spherical particle will vanish. Present numerical results at Tr 5 10e5 are in good agreement with other numerical results of flow around the rotating sphere at no-slip condition.