One of the common problems observed in the shell and tube heat exchanger is erosion of shell of surface due to the force of fluid which is entering through header of the shell. This problem of erosion could be minimized by placing the modifiers at near inlet of shell which will divert the flow direction. The objective of the project is to analyse the flow characteristics at the inlet header of shell and tube heat exchanger with modifiers using the Computational Fluid Dynamics tool. A heat exchanger is a device that is used to transfer heat energy between two fluids. Shell and tube heat exchanger is built up of a bundle of round tubes mounted in a cylindrical shell with the tube axis parallel to that of the shell. One fluid flows inside the tubes, the other flows across and along the tubes. The heat exchanger would be modelled with modifiers of opening angle 30degree, 45 degree and 60 deg and curved profile. The parameters such as wall shear, intensity of turbulence, pressure variation would be considered for analysis. A comprehensive comparative analysis would be carried out for optimizing the position of modifier. © 2015 Elsevier B.V., All rights reserved.