Geometric effects on lateral transport induced by slanted grooves in a microchannel at a low Reynolds number

Abstract

Flow over slanted grooves can generate a high degree of lateral transport by means of cross-movement of fluids along the groove. However, the quantitative relationship between the groove features and the cross-movement of fluid is rarely reported. We investigate the geometric effects of the groove on the cross-movement by computing the lateral displacements of particles in the cross section of the channel for varying geometric parameters of the groove, such as the depth, width, and angle. We identify the region of the cross-movement in the cross section of the channel, discuss the mechanism of material folding by the grooves, and touch on the validity of the effective slip model. The experimental results show the effect of the groove depth on the lateral transport of dye solutions, which confirms the numerical results. At high groove angles, the lateral transport can be characterized by complex swirling structures, and the swirls are quantified by the characteristic number of revolutions inside the groove. (C) 2013 Elsevier Ltd. All rights reserved.