Fully developed turbulent flow in ducts with symmetric and asymmetric rough walls

A low computational cost semi-analytical procedure is presented for the sol ution of incompressible fully developed turbulent flow through symmetric an d asymmetric ducts with rough walls. Using a modified algebraic turbulence model to represent the influence of rough surfaces, the flow field in ducts with different wall roughnesses is solved. The velocity distribution and t he friction factor in two different geometries, circular duct and parallel plates, are presented and compared with experimental and numerical data ava ilable in the literature, and a satisfactory agreement is obtained. (C) 199 9 Elsevier Science S.A. All rights reserved.