International Journal of Applied Engineering Research ISSN 0973-4562 Volume 11, Number 14 (2016) pp8288-8292 © Research India Publications. http://www.ripublication.com 8288 Finite Element Analysis on Thermal Performance of Exhaust Gas Recirculationby using CFD Ranjit Shrestha 1 ,Yoonjae Chung 1 , Ahrum Han 2 , Seungsu Hong 2 and Wontae Kim 1✝ 1 Division of Mechanical & Automotive Engineering, Kongju National University, Cheonan, Korea 2 R&D Center, Mano Inc., Cheonan, Korea ✝ Corresponding Author: Abstract The exhaust gas recirculation (EGR) plays a very effective role to reduce the emitted Nitrogen Oxide (NOx) from internal combustion engine by reducing the combustion temperature. The recirculate gases are subjected to cooling to increase the effectiveness of the strategy.Computational fluid dynamics (CFD) providesthe qualitative and quantitative prediction of fluid flows by means of mathematical modelling, numerical methods and software tools. Computational simulation is becoming more and more important due to lower cost and acceptable accuracy with minimum error.In this study, computational investigation was conducted for the thermal performance of shell and tube type EGR. ANSYS 15 workbench design modeller was used for 3-D modelling of EGR and Fluent was used to solve and simulate the flow fields and temperature distribution of the fluids inside the EGR cooler. Furthermore, the thermal performance of the EGR was analysed, compared and verified by the experimental results. Keywords:Exhaust gas recirculation (EGR), Computational fluid dynamics (CFD), Shell and tube EGR, Thermal performance, Finiteelememt analysis INTRODUCTION The NOxemission from internal combustion engines remain a major problem from the pollutant point of view. Over recent past years, stringent emission legislations have been imposed on NOx, smoke and particulate emissions emitted from automotive engines world wide.In order to meet the environmental legislations, it is highly desirable to reduce the amount of NOx in the exhaust gas [1-4]. One of the most widely used, reasonably priced and consolidated techniques to reduce NOx emissions is the EGR system.EGR is a heat exchanger in which cooling water is maintained at a constant temperature to absorb heat from the incoming exhaust gas. The temperature of the exhaust gas re-circulated is kept cooler than the engine exhaust and warmer than the intake air charge.EGR system recirculate a fraction of the exhaust gases, under certain engine operating conditions, to the intake manifold, where gases are mixed with fresh air, and thus the subsequent combustion process begins with a lower oxygen concentration. The mixture reduces the peak flame temperature and consequently decreases NOx formation[5-8]. EGR used in both spark ignited (SI) and compression ignition (CI) engines with the purpose to reduce NOx emissions has been preferred over other methods of charge temperature reduction for its advantages such as reduced oxygen availability, increased specific heat, relative ease of implementation and effectiveness[9,10].CFD provides a qualitative and quantitative prediction of fluid flows by means of mathematical modelling, numerical methods and software tools. CFD enables scientist and engineers to perform numerical experiments in a virtual flow laboratory.Hence, CFD is one of the ways to virtually design and run the simulation experiment without the need to physically build the model. This process can be done by CFD modelling using commercial software and it is very much cheaper compare to physical model building. CFD has been successful in carrying out the simulation on many engineering problems such as gas turbine, industrial furnace, boilers, internal combustion engines, flameless combustor and other engineering applications[10-16]. This paper deals with the study of thermal performance of EGR system with CFD simulation. The flow behaviour of hot exhaust gases and water coolant moving inside the EGR cooler is simulated and analysedwith ANSYS FLUENT 15.0. CFD calculation and mathematical processes are governed by fluid flow governing equations. THEORY The application of fundamental law of mechanics to a fluid gives the governing equation for a fluid. The conservation of mass can be expressed as[17-20], (1) where, ρis the fluid density; t denotes time; V= {u, v, w} is velocity vector whereu, v and ware the velocity components alone with the x, y and zaxes, respectively; and are differential operators, (2) From the law of momentum conservation, the momentum varying rate (with respect to time) of the fluid element equals the external force acting on the element block, i.e., the Navier- Stokes equation, (3) where, P is the fluid pressure, F is the bulk force vector of the fluid. The energy increment of the fluid element equals the sum of the entered heat flux and the power generated by both the bulk