軸対称回転容器内流れのスチュワートソン層と微粒子軌道(流体工学,流体機械)

In order to consider the rotating source-sink flow which is applicable to an accurate wet-type centrifugal classification system, we numerically studied the structure of through-flow within a rotating axisymmetric container, focussing on the almost rigidly rotating flow developing with decreasing Ekman number for a very small Rossby number. Consequently, in the almost rigidly rotating flow in a rotating squarish doughnut-shaped container with the source and sink at corners of outer and inner walls, an axial velocity component was found to singularly increase in magnitude near the source and sink. Also, the axial-transport thickness defined by an axial velocity component and the displacement thickness defined by an angular momentum were found to correspond to E1/3- and E1/4-Stewartson layers, respectively. Next, we numerically studied particle motions in the almost rigidly rotating flow in a radially-inward-expanding axisymmetric container, and obtained the result that the cut size can be controlled by angles of walls with hardly decreasing the classification accuracy in this flow field.