In oil and gas production, annular flow is a common flow regime found in wells and pipelines. Predicting erosion in multiphase flow is a challenging task as so many factors and phase interactions are involved. Computational Fluid Dynamics (CFD) offers a way to predict multiphase flow erosion. This present work shows how this state-of-the-art erosion model is applied to a 3 inch elbow to calculate erosion under annular flow conditions and how an improved 2-D model is developed for calculating erosion in annular flow for elbow geometries. The CFD predicted results are compared with experimental data and good agreement is observed. Flow solution from CFD and collected erosion data are also utilized to improve a 2-D model for annular flow application. It is shown that the combined CFD and 2-D model is a promising erosion prediction procedure for annular flows.