Laminar drag reduction in microchannels with liquid infused textured surfaces

Liquid infused surfaces (LIS) achieve non-wetting properties through asperity structures containing pockets of a lubricating liquid rather than air. Although studies have demonstrated several potential applications of LIS, the effect of liquid infused texture on the flow of liquid in microchannels has not been systematically addressed. The present work focuses on the effect of liquid-infused texture geometry and the infused liquid properties on the flow characteristics of a bulk fluid in rectangular and round microchannel geometries. Considering four different textured geometries of transverse ridges, longitudinal ridges, in-lined square posts and staggered squares, a detailed parametric study is presented to assess the resulting drag reduction and friction factor, expressed in terms of the Poiseuille number, on the flow in microchannels. The effect of geometrical parameters is investigated for different asperity solid fraction (phi(s)), asperity height ohs) and channel thickness (H) or tube diameter (D), while the effect of the infused fluid is studied in terms of a ratio of its viscosity relative to the viscosity of the flowing bulk fluid. Based on the results of the parametric study an extension of the conventional Moody diagram for non-wetting surfaces is developed. Further, a design of experiments study is conducted to relate the drag reduction and Poiseuille number to the various governing parameters, using which conditions that maximize drag reduction are identified. (C) 2020 Elsevier Ltd. All rights reserved.y

Automated summary

This study investigates the effect of liquid-infused surfaces on the flow characteristics of bulk fluid in microchannels, focusing on the geometry and liquid properties. A detailed parametric study is conducted to assess drag reduction and friction factor on flow in microchannels, leading to the development of an extended Moody diagram and identification of conditions that maximize drag reduction through a design of experiments study.