LAMINAR FLOW IN A UNILATERALLY ROUGH CHANNEL
This paper deals with an analytical and experimental investigation of laminar sheet flow between a smooth and a rough wall. As such, the material presented may be of special interest within the context of hydrodynamic lubrication. The dynamic and kinematic properties of the flow are described by a newly conceived “reduced Reynolds number”, and the two length parameters of, respectively, “relative roughness” and “steepness of roughness”. The equations of motion are solved by the finite element method for the case of sinusoidal roughness, and corresponding measurements are obtained in a specially designed two-dimensional wind-tunnel. Good agreement is found to exist between numerical and experimental results. The pattern of streamlines and velocity profiles reflect the influence of the three similitude parameters and thereby underline the important role played by surface texture in laminar sheet flow.