This paper presents the numerical analysis on the impact of downstream edge angle of chamfered rectangular transverse rib on the thermal performance of solar air heater (SAH). A two-dimensional CFD simulation study is carried out to determine the influence of downstream edge inclination angle of chamfered rectangular rib on the thermal and flow characteristics of SAH. The analysis is carried out under constant heat flux conditions for varying flow Reynolds number of 9000 and 19000. The ribs are modified on its rear edge where the angle of the edge is varied from 45° to 135°. The angle of inclination of downstream edge of transverse rib has a significant effect on heat transfer characteristics of SAH system. The friction factor is not significantly affected by the downstream inclination angle considered in the analysis. The Nusselt number enhancement is about 1.85 times for the downstream edge angle of 135° as compared to that of 1.09 for 45° angle.