Clogging behavior of an elongated bubble in uniform and diverging microchannel

Abstract

A numerical investigation has been performed to make a comparative study of clogging and detachment behavior of an elongated bubble during adiabatic flow through a uniform and diverging cross-sectional microchannel. The adiabatic gas–liquid two-phase flow has been numerically solved using volume of fluid approach in a finite volume code. Simulations have been made to investigate the effects of wall wettability, surface tension, and flow velocity on the bubble dynamics for both the configurations of microchannel. The net pressure drop across the bubble in the diverging channel has been calculated analytically and the results have been compared with numerical results. In both types of channels, the bubble shape goes through a transient stage followed by a steady and stable shape. The change in bubble shape during transient phase depends on the surface wettability, flow velocity, and the confinement of the channels. The bubble attains the symmetrical shape earlier in diverging channel. The formation of liquid film between the bubble and the wall plays an important role in the clogging behavior and movement of the bubble. Wall wettability has less impact on the pressure drop characteristics in the diverging channel.