The article investigates turbulent flow characteristics and heat transfer enhancement on periodically arranged semicircular ribs fitted in a rectangular channel. The channel was fabricated as the aspect ratio of AR = 5, rib height to hydraulic diameter ratio was 0.07, and rib height to channel height ratio was set as e/H = 0.117 for various rib pitch to rib height ratios between 8 and 14. In order to predict realistic phenomena of heat transfer and flow characteristics near the wall, shear stress transport k- turbulence and v(2)-f turbulence models were chosen. The results of numerical analysis show turbulent flow characteristics, heat transfer enhancement, and the effect of friction as observed experimentally. The results shows that turbulent kinetic energy (k) is closely related to diffusion of recirculation flow, and results from v(2)-f turbulence model simulation are in agreement with experimental values.