Limitations of the near-wall k-epsilon turbulence model

Comparisons are given at two different Reynolds numbers between the measured turbulent kinetic energy in channel flow, and the predictions of several near-wall variants of the k-epsilon closure. Included among these are new calculations based on a form of the epsilon equation that is consistent with the physically correct boundary condition. It is observed that all of the approaches fail to account for the large peak k value in the wall region that is evident in the experimental data. By contrasting the computed energy budget with its measured values, it is shown that this defect may be attributed to a fundamental inconsistency in the commonly used model for the pressure diffusion term in the k equation near the boundary.