角柱列を挿入した平行平板間流れの数値解析

第2報, 計算結果が一意性を持つ場合の判定条件

抄録

Two-dimensional numerical computation has been performed for unsteady laminar flow. Spatial periodic boundary conditions were adopted in the streamwise direction and adequacy of its treatment was particularly studied. The following results were obtained. When the numerical result fluctuates with the computational domain size, various low frequency components are observed remarkably in the streamwise velocity of the calculated result. Compared with channel flow obstructed by single rod of the same size, intensities of velocity fluctuation in this study are relatively high, and their distribution throughout the flow field is rather uniform. Averaged kinematic energy of the velocity fluctuation is adopted as a key parameter, and a discrimination map of the validity of numerical results is presented with a time scale ratio between mean flow and velocity fluctuation, the rod pitch and the blockage ratio. The time scale ratio can be well correlated with a geometric parameter obtained from the flow configuration, and the discrimination map can be converted to a map described with the geometric parameter and the channel Reynolds number.