Numerical analysis of 3-D flow past a stationary sphere with slip condition at low and moderate Reynolds numbers

Computations are performed to determine the steady 3-D viscous fluid flow forces acting on the stationary spherical suspended particle at low and moderate Reynolds numbers in the range of 0.1 <= Re <= 200. A slip is supposed on the boundary so that the slip velocity becomes proportional to the shear stress. This model possesses a single parameter to account for the slip coefficient lambda ( Pa. s/m), which is made dimensionless and is called Trostel number ( Tr = lambda a/ mu). Decreasing slip, increases drag in all Reynolds limits, but slip has smaller effects on drag coefficient at lower Reynolds number regimes. Increasing slip at known Reynolds number causes to delay of flow separation and inflect point creation in velocity profiles. At full slip conditions, shear drag coefficient will be zero and radial drag coefficient reaches to its maximum values. Flow around of sphere at full- slip condition is not equal to potential flow around a sphere. Present numerical results corresponding to full slip ( Tr ! 0) are in complete accord with certain results of flow around of inviscid bubbles, and the results corresponding to no-slip ( Tr -> infinity) have excellent agreement with the results predicted by the no- slip boundary condition.