CFD simulation of turbulent flow and heat transfer over rough surfaces

A three-dimensional numerical study of computational fluid dynamics and heat transfer simulations is conducted for a turbulent flow over rough surfaces. Numerical solutions were obtained using commercial software ANSYS FLIJENT 6.3.26 thr a Reynolds number Re=6760. The working fluid was air (Pr congruent to 0.71). Mean velocity, turbulent kinetic energy and local Nusselt numbers are obtained. It is seen that present hydrodynamic results are in good agreement with (DNS) results. The thermal results obtained show that the use of the undulations has a great influence on the heat transfer. This undulation increases the heat exchange between the fluid in motion and the heated wall. The result shows that the double undulation compares to the simple undulation help to increase Nusselt number by 10%. (C) 2015 The Authors. Published by Elsevier Ltd.