This paper presents the simulations of turbulent flow with heat transfer through channels with surfaces of complex configurations like wavy, triangular and rectangular ribbed walls using the open source CFD code OpenFOAM. The simulations were carried out using low Re k-ε turbulence model. OpenFOAM simulations predicted the flow structure and temperature distribution near the wavy wall, moreover the critical amplitude of the wavy wall, where the heat transfer is maximum.