Elbow pipes are crucial parts of many fluid transport systems, including ones used in the oil and gas industry. The curved shape of such pipes induces centrifugal forces on the internal flow, ultimately affecting the flow velocity and creating pressure differences within the elbow. The present study is an investigation of the effects of elbow pipes on the flow, and how changing the curvature ratio of an elbow pipe affects the internal flow. The study entails three-dimensional numerical simulations and analysis for laminar internal flows within pipes of varying curvature ratios. For laminar flows, the simulations are based in 4 Reynolds numbers ranging from 200 to 2000 and 3 curvature ratios Ro = 2.8, 5.6 and 11.2.