Computational study of inertial effects in toroidal and helical microchannels

Abstract

Fluid flow characteristics and their dependence on device geometry and fluid parameters were studied in this article. We computationally examined three types of microfluidic channel geometries: torus, cylindrical annulus with squared cross-section, and helix. Several parameters varied over simulations: kinematic viscosity of the fluid, the velocity of the fluid, curvature radius, cross-section dimension, and pitch for helical channels. We analyzed the velocity distribution of the primary flow, as well as shape of Dean vortices for secondary inertial flow, and in case of helical channels, we analyzed also S-shaped streamlines within non-perpendicular cross-section. We analyzed also dependence of the secondary flow velocity and vorticity on average velocity of primary flow. We could confirm that the Dean effect is present in our numerical simulations, and it can be further investigated as a sorting tool for cells in suspension.