International Journal of Engineering Science and Computing, June 2016 7569 http://ijesc.org/ DOI 10.4010/2016.1789 ISSN 2321 3361 © 2016 IJESC ` CFD Analysis of Mass Flow under Induced Non-Uniformity through Heat Exchanger Kirti Onkar Prajapati 1 , Harshwardhan Uddhage 2 , Sanjay Kumbhare 3 , Krishna Kumar Thakur 4 PG Research Scholar 1 , 2 , Assistant Professor 3 , Associate Professor 4 Department of Thermal Engineering Patel College of Science & Technology, Bhopal kirtiop@gmail.com 1 , harshwardhan.uddhage@gmail.com 2 , sanjaykumbhare2709@gmail.com 3 , krishnakumarthakur@gmail.com 4 Abstract: Heat exchanger is mainly associated with transfer heat from one fluid to another fluid either in direct contact with each other or separated by wall. The heat exchangers characteristics are concerned with the rate of heat transfer between the fluids with assuming the flow to be uniform throughout the core of the exchanger. But in actual practice it is usually the flow Non-uniformity that occurs and adversely affects the Heat Transfer rate and heat exchange properties of the heat exchanger. The major non-uniform flow is caused due to poor header design or restrictions in flow at microscopic level as a result of manufacturing operations on the surface. The CFD analysis of Heat exchanger is achieved considering the concept of Viscosity induced flow Non-Uniformity through the exchanger tubes. With the application of Computational Fluid Dynamics package FLUENT relative analysis pertaining to Non- uniform flow is carried out. The matter of interest of this paper is to analyze the heat transfer related to two mean temperatures namely cross-sectional and adiabatic mean temperature. Index Terms: Algorithm, Analysis, CFD, Convergence, Fluent, Gambit, Grid, Heat flow, Models, Non-uniform, and Solver. I. Introduction Shell-and-tube heat exchangers are the most versatile type of heat exchanger. They are used in many industrial areas, such as power plant, chemical engineering, petroleum refining, petrochemicals industries, food processing, paper industries, etc. Shell and tube heat exchangers provide relatively large ratios of heat transfer area to volume and weight and they can be easily cleaned. They have greater flexibility to meet any service requirement. The shell-and-tube heat exchangers consist of a bundle of tubes enclosed within a cylindrical shell. One fluid flows through the tubes and a second fluid flows within the space between the tubes and the shell. Heat exchangers in general and tubular heat exchangers in particular undergo deterioration in performance due to flow non-uniformity. The design and Analysis of Heat Exchanger is carried out with a major consideration in terms of Mass flow of the fluid to be distributed uniformly at the inlet of the exchanger on each side that is, fluid side and throughout the core. But, in actual practice, the flow Non-Uniformity is more common and significant which reduces the desired heat exchanger performance. Non-uniform flow is defined as of the mass flow rate on one or both sides in any of heat exchanger ports and in the heat exchanger core. The prime non-uniform flow occurs at the macroscopic level. The overall flow non-uniformity is independent of local geometry of the heat transferring surface. Flow non-uniformity can be induced by basic geometry, operational conditions, passage to passage flow imperfections and instability. One class of flow non-uniformity is a result of geometrically non-ideal fluid flow passages or non-ideal exchanger inlet/outlet manifold, nozzle, and referred as geometry induced flow non-uniformity. Investigation is carried out to study the cross sectional mean temperature and adiabatic mean temperature profiles in the computational domain, tubular single pass heat exchanger for flow Non-Uniformity or uniform mass flow distribution on tube side and ideal plug flow on shell side. It is investigated that for uniform mass flow distribution on tube side and ideal plug flow on shell side, there is no difference between the cross-sectional mean temperature and adiabatic mean temperature. For the analysis purpose a shell and tube heat exchanger is considered with pure axial flow on the shell side and non-uniformity on the tube side. II. Need For Analysis This numerical analysis is done for the in-line tube arrangement with different number of tubes. A finite volume numerical method is applied to predict the conjugate heat transfer and fluid flow characteristics with the aid of the computational fluid dynamics (CFD) commercial code, FLUENT. The governing equations for the energy and momentum conservation were solved numerically with the assumption of three-dimensional steady flow. An effective model, the standard based k-ε turbulence model was used in this investigation. The available relevant literature is quite limited With respect to the analytical and it is still difficult to predict the physics of the flow non- uniformity within the circular tube banks. Therefore, temperature distributions within the bundle were studied numerically. In thermal systems, the constraints arise largely from the conservation laws for mass, momentum, and energy, and from limitations of the material, space, and equipment being used. However, these usually lead to nonlinear, multiple, coupled, partial differential equations, with complicated geometries and boundary conditions in typical systems of practical interest. Other complexities may also arise due to the material characteristics, combined thermal transport Research Article Volume 6 Issue No. 6