Skin friction and heat transfer for combined roughness and mass addition
Abstract
A finitedifference solution to the boundary layer equations for flow over rough surfaces with mass addition is presented. The equivalent sandgrain roughness height is not needed, but rather the actual roughness height and spacing is used. The boundary layer equations are cast in a form to account for the blockage effects of roughness elements. The roughness effect is described by a sink (form drag) term in the momentum equation and a source term in the static enthalpy equation. A twolayer algebraic mixinglength model that contains very little empiricism but yet is capable of accounting for roughness height, spacing, geometry, and mass addition is presented. Good agreement is shown to incompressible and compressible flatplate data with combined roughness and blowing.
 Publication:

IN: Laminar turbulent boundary layers; Proceedings of the Energy Sources Technology Conference
 Pub Date:
 1984
 Bibcode:
 1984ltbl.proc....9C
 Keywords:

 Boundary Layer Flow;
 Heat Transfer;
 Mixing Length Flow Theory;
 Skin Friction;
 Surface Roughness;
 Turbulent Flow;
 Blowing;
 Boundary Layer Equations;
 Finite Difference Theory;
 Flat Plates;
 Prandtl Number;
 Stanton Number;
 Two Dimensional Flow;
 Fluid Mechanics and Heat Transfer