単純形状キャビティに流入する固液混合体の流動現象

抄録

The solid-liquid two phase flow influences on the properties of materials such as the semi-solid metals or the particulate-reinforced metal matrix composites. Therefore the flow phenomena of water-polystyrene mixture with high fraction solid in a suddenly enlarged cavity were examined. The mixture in an airtight vessel was ejected vertically into the cavity by increasing the internal pressure of the vessel.
The shape of free surface of the mixture became more stable with increasing fraction solid. The main reason of suppressing the disturbance of the free surface is not the increase of the mean relative viscosity but the increase of fraction solid of the region near the free surface. The concentration of particles decreased at the center of rotary motion in the early stages of filling and at the boundary between the rising particles and the piled-up particles, which existed above filling ingate. It was the inertial force of particles that held the low-concentration region at the center of rotation. The low-concentration region above the ingate is caused by the collision of particles.