Abstarct: An alternative for rib Turbulators in past recent years for internal heat transfer enhancement is surfaces with dimple and/or protrusion. These two techniques induce less pressure drop compared to rib, which leads to higher thermal performance. In the present study, flow characteristics and heat transfer enhancement for surfaces with V-shaped dimples and/or protrusion is investigated using numerical methods. There have been four cases with different configuration of V-shaped concavities. The objective of this study is to enhance heat transfer and flow mixing, combining these two techniques on different walls of channel. All the results are obtained using standard k-ω model. The combination of dimples and protrusion on different walls of channel is the main design parameter. The inlet Reynolds number ranges from 10,000 to 60,000 conducted for four cases with different internal concavities. Measurements indicated that in lower Reynolds (Re=10,000) highest Nu/Nu0 belongs to the case which only opposite walls of channel were dimpled. Whereas other cases approximately induce the same amount of Nu/Nu0. By increasing Reynolds number to 20,000 all cases show similar trend. The Nu/Nu0 increases for all of cases. As the Reynolds goes higher, all cases show decrease in heat transfer ratio except the case, which sidewalls are also dimpled, which shows increasing trend in heat transfer which is due to two additional counter-rotating vortices induced in sidewalls. Moreover, in all cases by increasing in Reynolds number, friction factor increases. Therefore, the highest overall thermal performance belongs to the case which sidewalls as well as opposite walls.