Presentazioni e Articoli Tecnici

The effect of finite boundaries on the drag experienced by a rigid sphere settling along the axis of cylindrical tubes filled with Carreau model fluids has been examined systematically over a wide range of condition.

As expected, the presence of finite boundaries leads to an increase in the drag force exerted on a falling sphere thereby retarding its descent due to the obstruction caused by the sphere and the corresponding changes in the velocity field close to the sphere. Nonetheless, the wall effect is less significant as the power law index decreases and/or the Carreau number increases, i.e., increasing extent of shear-thinning behavior.

Additionally, the severity of bonding walls affects the wake characteristics. The present calculations show good agreement with experimental reports available in the literature.