Control of air bubble cluster by a vortex ring launched into still water

2015 Fiscal Year Final Research Report

• Project/Area Number: 25420114
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Fluid engineering
• Research Institution: Nagoya University
• Principal Investigator: Uchiyama Tomomi 名古屋大学, 未来材料・システム研究所, 教授 (90193911)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 流体工学 / 混相流 / 気泡 / 操縦 / 渦輪 / 可視化

Outline of Final Research Achievements

An experimental study searching for the possible generation and transport of a bubble cluster by a vortex ring in water is performed. A vortex ring is launched vertically upward into a water tank by discharging the water from a cylinder mounted at the bottom of the tank with a piston. Air bubbles are successively injected into the vortex ring from a needle attached to the cylinder outlet. The generation of bubble cluster and transport of the cluster by the vortex ring can be classified according to the strength of the vortex ring and the air volumetric flow rate. When the strength of the vortex ring is low, the bubbles are less affected by the vortex ring and instead rise with the buoyant force at a higher velocity than the vortex ring. With an increase in the strength of the vortex ring, the bubbles are entrained in the vortex core and form a cluster. The convection velocity of the vortex ring is scarcely affected by the entrained bubbles, but the radius is enlarged slightly.

Free Research Field

流体工学