Abstract: In this paper, the energy equation and the standard k ε turbulence model were added to an in house high resolution code, which was for calculation of laminar flows using unstructured finite volume method with selection of high order schemes. The procedure was validated by calculating natural convection in enclosures and turbulent flow over a heated backward facing step. For comparison, these cases were also computed by a commercial software package, the FLUENT, using the same meshes. The results obtained by the present procedure agreed well with the benchmark solutions. For the FLUENT, however, worse agreements with the benchmark solutions were obtained. These confirmed the high resolution of the numerical procedure.