AbstractA recent laser doppler anemometer study, by other researchers, of turbulent flow through a sudden expansion has been simulated using a kinetic energy of turbulence‐dissipation rate of turbulence (k‐ ϵ) model. The near wall region was modelled in two different ways; using wall functions (WF), and a low‐Reynolds number (LRN) formulation.The reattachment length under particular flow conditions was obtained. Radial profiles for the mean axial and radial velocity, turbulence kinetic energy and Reynolds shear stress were determined for six locations downstream of the sudden expansion. Both models performed reasonably well in predicting the flow with the LRN approach performing slightly better than the WF approach near to the wall.The application of the LRN approach to the calculation of local mass transfer rates in wall bounded complex turbulent flows is demons