Study of multiphase flow inside straight and spiral microchannel and effect of two phase flow on Dean’s vortices

Abstract

A combined experimental and numerical simulation study of gas–liquid two-phase flow inside straight and spiral microchannels is presented. Dynamics of Taylor bubble formation was investigated in both types of channels and it was canvassed that presence of centrifugal force in spiral channel has consequential influence on the Taylor bubble dynamics. Effect of gas–liquid flow ratio and hydrophobicity of channel wall on the Taylor bubble formation was also investigated through numerical simulations. Formation of Dean's vortices inside spiral microchannel was shown via 3D CFD based simulations. Quantification of the strength of such vortices was done by calculating vorticity (ω) which is the curl of the velocity vector field. The effect of curvature on the formation of Dean's vortices was shown using Dean Number (De) and Dean velocity (VDe). The effect of two phase flow on the vorticity was also emphasized by presenting a comparative study with single phase flow. Presence of Dean's vortices inside such spiral micro-channel can be utilized in many futuristic micro-contrivances.