Experimental Study of Slip Flow at the Fluid-porous Interface in a Boundary Layer Flow

Abstract

A boundary layer flow over a porous laminated flat plate is analyzed. We model the 2D porous region as an array of circular cylinders kept in the span-wise direction of the flow. The porosity(φ) of the models is controlled through the center-to-center distance between the cylinders in the array. Experiments are performed on φ = 0.65 and φ = 0.80 porosity models for a range of Reynolds numbers, Re. The study focuses on the experimental confirmation and quantification of the slip velocity at the porous fluid interface. The stream wise velocity in boundary layer flow is measured using a LDV. The measurements are done at various stream-wise locations with sufficient spatial resolution in the vertical distance. The profiles thus obtained are averaged over a Representative Elemental Volume (REV) to even out the local disparities. The slip velocity is found to increase with increase in porosity and is weakly dependent on Re.