A PARAMETRIC STUDY ON DRAG REDUCTION USING ENGINEERED MICROTEXTURES IN VISCOUS LAMINAR FLOW

The topic of friction reduction has been studied through the decades for numerous engineering applications that involve internal and external flows. Inspired by the natural surface structure of different plants and animals, engineered microtexturing of surfaces is one of the effective ways of reducing the drag. By introducing different texture geometries, the flow behavior close to the solid boundary can be altered and thus manipulated towards achieving a reduced net drag force on the surface. Despite considerable research on the subject, most works have concentrated on optimization of the surface texturing for maximizing the friction reduction and minimizing the pumping power requirements, and less attention has been paid to characterization of the flow and boundary layer in the vicinity of the wall, especially in laminar regime. In this work we investigate the role that microtexturing has on friction reduction under low to moderate Reynolds numbers (Re). We perform a parametric study on the shape and dimensions of the surface textures and investigate the boundary layer and streamline behavior as well as the local shear stress and pressure distribution along the solid-fluid interface under different flow conditions. The outcomes of this work will provide a guideline for optimal design of artificial textures with major implications for many engineering applications such as microfluidic systems used in thermal management and biochemical diagnostics.