回転二重円筒内流れの直接数値計算と実験との比較

抄録

To obtain a flow development process which is important for turbulent generation, we directly simulated the three-dimensional circular Couette flows with high Reynolds number using the third-order upwind finite difference scheme. In the experiments we observed flow states by a visualization technique. The results of the simulations are in fairly good agreement with the experiments. At the very early stage, the cells and vortices appear near the inner cylinder. The distribution of the centrifugal force caused by the velocity distribution makes the vortices grow to the outer cylinder. When the vortices have reached to the outer cylinder, they begin to interact with each other. At that moment, the flows become turbulent or chaotic, and soon after that the turbulent or chaotic flows disappear and new cells, with a height two or three times higher than the former cells, appear in the whole entire region of the flow. But in the case of higher Reynolds number (Re=1500), turbulent flows still exist in a cell. The flows become steady states with velocity fluctuations.