Impact of trapezoidal ribs on the performance of solar air collector: A numerical solution with optimized rib dimensions for better performance

• The impact of trapezoidal ribs over the absorber plate of the solar air collector was investigated. • Dimensions of trapezoidal ribs were proposed based on 108 sets of simulation results. • The output parameters Nusselt number ( Nu ), Nu ratio and thermo-hydraulic performance index were evaluated for all 108 simulations. • The Nu of trapezoidal ribs increased to 2.663 times more than the flat plates. • The proposed dimensions are rib pitch ( p ) = 140 mm, rib height ( e ) = 4 mm and rib angle ( α ) = 38.66°. In the present study, a 2D numerical analysis of the solar air collector (SAC) of an indirect solar dryer having trapezoidal corrugations on the absorber plate was performed. Corrugation pitch, p (twelve values ranged from 20 to 160 mm) and height, e (six values ranged from 1 to 10 mm) were varied and analyzed for six values of Reynolds numbers ( Re ). The output characteristics such as Nusselt number ( Nu ), friction factor ( f ) and thermo-hydraulic performance index ( T hp ) were calculated for different p, e and Re . The total work was categorized into two parts (part-I for optimizing p and part-II for optimizing e ). 18 domains (twelve for part-I and six for part-II simulations) were generated and 108 simulations were executed to find the optimum dimensions ( p, e and corrugation angle, α ) of the corrugation. ANSYS Fluent-v15 was used to solve the problem. The maximum Nu for the corrugated sheet was 2.663 times greater than the flat absorber plate. The maximum T hp range was from 1.435 to 1.699 and obtained at the optimal values of p = 140 mm, e = 4 mm and α = 38.66° The numerical results were compared with the existing literature.