The present work reports a computational fluid dynamic analysis of core annular flow through return bends. Core annular flow of lubricating oil and water has been simulated using FLUENT 6.3.26. A satisfactory trend matching is observed between numerically obtained phase distribution and experiments. A comprehensive study has been made to generate the profiles of velocity, pressure, and volume fraction over a wide range of oil and water velocities. It has been observed that the oil core may foul the bend wall under certain operating conditions. Through computational simulations the operating zone safe from the risk of fouling has also been identified. (C) 2011 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.