Vortex transition in X-junctions

MAC INTYRE J. R.; HULIN J. P.; GOMBA, J. M.; AURADOU H.; CORREA, P. G.; CACHILE M.

Rio de Janeiro

Workshop; P. Correa, J. M. Gomba, J. Mac Intyre, M. Cachile, H. Auradou, J.P. Hulin. VIII Workshop in Microfluidics; 2018

PUC-RIO

Abstract: We study numerically the flow structure in 2 and 3-dimensional X-junctions. These devices consist of two channels intersecting each other at an angle 𝛼, where two identical liquids are dispensed in opposing directions. Vortexes are characterized in terms of the parameters 𝛼 and the Reynolds number (𝑅𝑒). We observe vortexes with axis point in the direction normal to the junction plane. The number of vortexes increases as 𝛼 decreases or 𝑅𝑒 growths. Also, we identify critical values of 𝛼?s that limit the maximum number of vortexes. We observe that the 3D flow differs from the 2D symmetry principally due to the appearance of a vortex with an axis parallel to outlet channel for high 𝛼 and 𝑅𝑒. This particular feature allows to improve the mixing of the fluids.