Vortex Simulation of Bubble Plume Around a Rectangular Cylinder
Tomomi Uchiyama and Tomohiro Degawa
This study is concerned with the numerical simulation for the bubble plume around a square-section cylinder. Small air bubbles are injected into still water from a nozzle below a square-section cylinder, and the rising bubbles induce a bubble plume around the cylinder. The side length of the cylinder is equivalent to the nozzle width. The two-dimensional vortex method for gas-liquid two-phase flow, proposed by the authors in a prior paper, is employed for the simulation. The bubbles injected from the nozzle rise vertically. The bubbles colliding with the front of the cylinder flow along the lateral sides, and they leave the cylinder. The bubbles above the cylinder rise in two lines. The water velocity on the horizontal cross-sections satisfies the similarity distribution around the plume centerline. The cylinder affects the water flow in the upper region. The water velocity and the strength for the large-scale eddies are lower than those of the plume without the cylinder. But the vertical component of the turbulent intensity is two times higher, and the water flow spreads more toward the horizontal direction.
Keywords: Numerical simulation, Vortex method, Bubble plume, Bubbly flow, Phase distribution, Lagrange method