Numerical Simulation of Scaling Effect on Bubble Dynamics in a Turbulent Flow around a Hydrofoil

Authors

Khajeh Nasir

Abstract

A Lagrangian-Eulerian numerical scheme for the investigation of bubble motion in turbulent flow is developed. The flow is analyzed in the Eulerian reference frame while the bubble motion is simulated in the Lagrangian one. Finite volume scheme is used, and SIMPLEC algorithm is utilized for the pressure and velocity linkage. The Reynolds stresses are modeled by the RSTM model of Launder. Upwind scheme is used to model convective fluxes. The Guassian Filter White Noise is incorporated to simulate the turbulent fluctuation velocities. The bubble diameter is found by the use of Rayleigh-Plesset equation. Various forces in the equation of motion of the bubble are considered. The Buoyancy, Saffman lift, drag, pressure, and change of volume forces are carefully applied. The effects of all of these forces on bubble path are also examined. The bubbles are created in the low pressure zones, and then traced in the flow field. It is observed that the bubble diameter is highly dependent on the mean stream pressure, and its location. The results are compared with the other published works, and have an acceptable accuracy.