Investigation of the thermo-hydraulic behavior of the fluid flow over a square ribbed channel

The thermo-hydraulic behavior of the air flow over a two dimensional ribbed channel was
numerically investigated in various rib-width ratio configurations (B/H=0.5-1.75) at different Reynolds numbers, ranging from 6000 to 18000. The capability of different
turbulence models, including standard k-ε, RNG k-ε, standard k-ω, and SST k-ω, in predicting the heat transfer rate was compared with the experimental results and it was
showed that the k-ε turbulent models best adapt with the measured data. Four main
parameters, namely, the Nusselt number, friction factor, skin friction factor, and the thermal enhancement factor were examined through the simulations. Results indicate that an increase in the Reynolds number caused the Nusselt number to increase and the friction factor to drop. It was found that the thermal enhancement factor augmented by an increase in the Reynolds number, and also, for a wider rib, i.e. at the higher the B/H ratio, a lower thermal enhancement factor was obtained.