Nowadays, many researchers works in fluid dynamics has been concentrated on determine the suitable turbulent model for better describing the flow structure and heat transfer characteristics in a specific problem, there are a lot of cases which are necessary about designation of an optimized turbulent model. In the present work, a ribbed roughened square duct has been investigated numerically. A two-dimensionally study has been done to evaluate the flow structure, heat transfer and computational efforts of seven turbulent RANS models, contemporaneously. In the Part 1 of this study turbulence models, which are used in these type of problems has been investigated. In the next, advantages of introduced turbulence models has been present and explained. The results of numerical simulations will be presented in the Part 2.