LBM simulation of bubble dynamics in a microchannel with multi-hole orifice plate

Abstract

This study employs a lattice Boltzmann method (LBM), incorporating the Allen-Cahn (A-C) phase-field model, to numerically simulate bubble dynamics in a microchannel with a multi-hole orifice plate. The influence of Weber number (We), non-dimensional bubble diameter (γ), and contact angle (θ) on bubble motion characteristics is thoroughly examined. Phenomena such as dynamic deformation, splitting, coalescence, and mass loss of the bubble during its passage through the multi-hole orifice plate are analyzed. Numerical results demonstrate that as the surface tension of the bubble decreases, corresponding to an increase in the Weber number, the bubble’s splitting process is facilitated as it passes through the multi-hole orifice plate. Additionally, two critical Weber numbers are identified in the study, delineating three different behaviors of the bubble as its passage, with these behaviors being influenced by changes in the non-dimensional bubble diameter. An increase in contact angle significantly prolongs the passage time t * , especially at higher We numbers. The most substantial increase of t * occurs at a Weber number of 27.24 when the contact angle shifts from 125 to 150 degrees, reaching a maximum of 64.13 %. Furthermore, the residual mass ratio of bubbles post-passage diminishes, recording its lowest at the highest Weber number and contact angle (We = 27.24, θ = 150°), standing at 0.71.