It is known that corrosion of pipelines is substantially increased in turbulent flows due to enhanced mass transfer coefficients. Mechanistic modeling of mass transfer effect in a turbulent flow presents a major challenge in corrosion simulation as it would require not only the solution to the Navier-Stokes equations but also the proper coupling between flow field and concentration field. In a water system coupling of flow and concentration fields is not an easy task because mass transfer boundary layer is usually deeply imbedded into the flow boundary layer. To reduce the mathematical complexity different correlations have been proposed in the past in order to simulate mass transfer effect. These correlations normally work well for fully developed flow in a straight pipeline but are lack of accuracy in complex geometry such as bends extractions and contractions which are not uncommon in industrial applications. In this research efforts were made to explore the mechanistic approach to simulate mass transfer coefficient in a disturbed turbulent flow system. The factors that would influence the accuracy of simulation are discussed. A mechanistic model was then built to simulate CO2 corrosion along a pipeline with a sharp bend where disturbed flow is experienced. Multiple physics involved in this simulation including chemical reactions electrochemical reactions mass transport momentum transport and potential distribution are coupled together and solved simultaneously. The modeling results suggest a comparable prediction with the other corrosion prediction package for straight pipe flow but give a higher rate around the bend where more turbulence is experienced.