水-微細固体粒子懸濁液の円柱周りの流れと抵抗減少効果 (<小特集>混相流の数値シミュレーションと新技術)

抄録

Experiments were performed on the flow past a circular cylinder in silica dioxide suspensions with C_w=0.5∼1.0wt% and in carbon black suspensions with C_w=0.3∼1.0wt%. Two cylinders with diameters between 10mm and 20mm located in a horizontal duct were tested in terms of the pressure distribution. It was shown that the separation point shifts downstream although the Strouhal number is almost the same as that of tap water. Consquently, from the result of an integration along the pressure distribution curve it is clarified that the drag reduction phenomenon in water/fine solid particle suspension is caused by the shift of the separation point in a certain Reynolds number range.