Influence of Gravity on Two‐Layer Laminar Flow in a Microchannel

Abstract

Abstract A microchannel forms a laminar flow if the fluid velocity is sufficiently slow. It is important to clarify the effect of gravity on laminar flow, since several microsystems require side‐by‐side laminar flow, which does not possess an interfacial tension. In this work, the influence of gravity on side‐by‐side laminar flow was quantitatively investigated using a computational fluid dynamics (CFD) simulation. As a result, a dimensionless parameter related to side‐by‐side laminar flow interfacial tilting was derived. Using this parameter, it was possible to estimate the interfacial tilting angle. The results reported here will be useful for microdevice design for chemical analysis, mixing, and chemical reactions.