Numerical Simulation of Entrainment and Transport of Gas Bubbles by Vortex Ring

The possibility to control the motion of small gas bubbles by a vortex ring is explored through a numerical simulation. Hydrogen bubbles with diameter of 0.2 mm are arranged in quiescent water, and a vortex ring is launched toward the bubbles. The behavior of the vortex ring and the bubble motion are analyzed. The diameter of the vortex ring at the launch is 42.5 mm, the Reynolds number is 500, and the bubble volume fraction at the launch is less than 0.04. The simulation highlights that the vortex ring convects in the bubble cluster with shoving the bubbles and that the bubbles are entrained and involved by the vortex ring. It also clarifies the changes of the diameter and circulation of the vortex ring.