準剛体回転成層流を用いた微粒子分級の基礎研究 : 第5報, 分級性能の数値解析

A numerical analysis on the classification of fine particles in an almost rigidly rotating flow is reported. The almost rigidly rotating flow between a coaxially rotating housing and a rotor can be regarded as a system for classification. The flow consists of an Ekman layer, an interior region, a Stewartson layer and a rigidly rotating region. The numerical method is composed of two stages. The first stage involves numerical simulation of the flow field using Navier-Stokes and continuity equations. The second stage involves computation of fine particle motion through the almost rigidly rotating flow. The mechanism of classification of the system is considered using the numerical results. The partial fractional efficiency of the system is computed for various particle diameters and flow parameters ; then the cut size and sharpness index of the system are estimated.