A comparative study of the effect of fin shape on mixed convection heat transfer in a lid-driven square cavity

In the present study, four fin shapes with similar area and width are proposed, and then mixed convection heat transfer in a lid-driven square cavity is numerically analyzed. The impacts of effective parameters such as Reynolds number(Re), Rayleigh number(Ra), and fin shape on the flow pattern and heat transfer are investigated. The average Nusselt number(Num) and the enhancement factor(η) improve when the Reynolds number of the lid-driven wall increases. Compared to the natural convection case, the results indicate that raising the Rayleigh number has a positive influence on the average Nusselt number but a negative influence on the enhancement factor. It is evident that the Γ-shaped fin in the cavity is best suited to augment the Num for various Rayleigh and Reynolds numbers. Moreover, while the T-shaped fin has the maximum η for Ra = 104, the Γ-shaped fin performs better for other conditions. The results illustrated that changing the fin shape from T to Γ improves the Num and η by 10.24% and 3.48%, respectively, for Ra = 5 × 105 and Re = 1500.