The present study is to investigate the heat transfer enhancement in a cylindrical heat exchanger using porous media. The heat exchanger is modelled by a cylindrical cavity (Shell) with inlet and outlet thermally insulated ports and five tubes which contain hot water and cold water flows in shell. The effect of porosity on heat transfer enhancement is studied at different mass flow rate 0.15, 0.2, 0.25 and 0.30 Kg/sec. The study about effect of porosity on heat transfer enhancement is done by both experimentally and CFD based and the results are compared with simple heat exchanger. In present study, two different types of porous materials are used and Porosity is taken as 80%. The effect of varying mass flow rate on outlet temperature, heat transfer coefficient, Reynolds number and Nusselt number has been investigated.