RÉSUMÉ

To predict rough wall turbulence without resolving rough geometry, spatial and Reynolds (double) averaged equations are modelled based on the two-component limit (TCL) second moment closure. The additional terms, namely, double averaged drag force and inhomogeneous correction terms arise due to the double averaging process. The double averaged drag force is modelled as the Darcy-Forchheimer form, and binomial expansion is applied to model the effects of fluctuating velocity on the double averaged drag force. The influence of the drag force on a pressure-strain term is modelled with TCL constraints. The developed model is calibrated in turbulence over randomly distributed semi-spheres and spray paint surfaces. The modifications of the skin friction in transitionally and fully rough regimes is confirmed to be successfully predicted by the developed model.