渦法による固液二相流中におかれた円柱まわりの流れの数値シミュレーション (<小特集>混相流の数値シミュレーションと新技術)

抄録

In this study, a two-dimensional solid-liquid two-phase flow past a circular cylinder was simulated using the boundary element method combined with the vortex method. As a result of calculation, the flow pattern and the motion of particles were shown. It was found that the motion of particles did not follow the fluid movement in the Karman vortex street. In the cases of mixing ratios 0.25%, 1.0% and 1.5%, there is no difference in the Strouhal number of vortex shedding between the two-phase flow and the single-phase flow. In the case of mixing ratio 2.3%, two patterns of vortex shedding, that is Karman vortex type and twin vortex type, were shown, and the value of the Strouhal number was approximately 40% lower than the Strouhal number in the single-phase flow. The spin speed and size of the particle had an effect on vortex shedding.