Advances in Chemical Engineering and Science, 2013, 3, 6-14 http://dx.doi.org/10.4236/aces.2013.34A1002 Published Online October 2013 (http://www.scirp.org/journal/aces) Theoretical Evaluation of Two-Phase Flow in a Horizontal Duct with Leaks Morgana de Vasconcellos Araújo 1 , Severino Rodrigues de Farias Neto 1 , Antonio Gilson Barbosa de Lima 2 1 Department of Chemical Engineering, Center of Science and Technology, Federal University of Campina Grande (UFCG), Campina Grande, Brazil 2 Department of Mechanical Engineering, Center of Science and Technology, Federal University of Campina Grande (UFCG), Campina Grande, Brazil Email: morganamva@gmail.com, fariasn@deq.ufcg.edu.br, gilson@dem.ufcg.edu.br Received July 23, 2013; revised August 23, 2013; accepted September 4, 2013 Copyright © 2013 Morgana de Vasconcellos Araújo et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. ABSTRACT The transport of oil and its derivates are done, mostly, by pipeline. The time to detect leaks has to be short for pre- venting big disasters in the nature and decreasing losses for industries. The techniques available for leak detection vary from visual inspection to the use of computational techniques such as mathematical modeling. This paper aims to study the fluid dynamics of two-phase flow (water-oil) in the pipe with leakage. The equations of the mass and momentum conservation are numerically solved by using the ANSYS ® CFX commercial code with the aid of a structured mesh of a horizontal pipe with three holes of leaks. The Eulerian-Eulerian model was adopted considering the oil as continuous phase and water as dispersed phase, and constant fluid properties. With profiles of pressure and volume fraction along the time in the pipe, the influence of leakage on the single-phase (oil) and two-phase (water-oil) was evaluated. Keywords: Two-Phase Flow; Numerical Simulation; Leakage; Pipeline 1. Introduction The transportation of oil and its derivatives are mostly conducted through pipelines that connect production fa- cilities, refineries and, in some situations, the consumer centers. The materials used for making pipes come through technological improvements, where there is a signifi- cant use of materials based on special steel, lighter and stronger. However, despite these advances, there are still problems with leaks in pipelines generating great interest from the oil industry in view of the high costs incurred by financial services, potential risks and environmental costs. Environmental disasters related to the oil spill in addi- tion to degrading the environment, are responsible for spending millions of dollars in remediation. In oil activities, particularly in transportation by pipe- lines, accidents have happened, causing financial and environmental losses. There are currently a variety of techniques available for the detection of leaks, ranging from simple physical in- spection by acoustic methods. Zhang [1] classified the detection methods into three categories: observation (perhaps the simplest and most ancient, is conducted through a visual inspection noting any ponding on the soil surface or anomalous growth of vegetation), direct detection (devices are used for the detection and location of leakage) and indirect detection (software is used based on mathematical models which allow to perform detec- tion by means of data flow like pressure, temperature, mass flow rate, etc.). The faster the identification of a leak in a pipeline, the faster valves are closed and the pumps will stop and, consequently, the greater the chances of avoiding a ca- tastrophe are. However, in order to do the detection and precise identification of the position of a leak, it is nec- essary to know the behavior(s) of fluid(s) within the duct which allows determination of pressure drop between two points being evaluated. According to Buiatti [2] the kind of leaks appearing in pipe networks can be divided into two classes: 1) Leak by “breaking” the tube—Occurs less fre- quently, but it is dangerous due to the amount of product spilled in the vicinity of the leak. However, these disrup- Copyright © 2013 SciRes. ACES