The presence of nanoparticles in heat exchangers ascertained increment in heat transfer. The present work focuses on heat transfer in a longitudinal finned tube heat exchanger. Experimentation is done on longitudinal finned tube heat exchanger with pure water as working fluid and the outcome is compared numerically using computational fluid dynamics (CFD) package based on finite volume method for different flow rates. Further 0.8% volume fraction of aluminum oxide (Al2O3) nanofluid is considered on shell side. The simulated nanofluid analysis has been carried out using single phase approach in CFD by updating the user-defined functions and expressions with thermophysical properties of the selected nanofluid. These results are thereafter compared against the results obtained for pure water as shell side fluid. Entropy generated due to heat transfer and fluid flow is calculated for the nanofluid. Analysis of entropy generation is carried out using the Taguchi technique. Analysis of variance (ANOVA) results show that the inlet temperature on shell side has more pronounced effect on entropy generation.
 Peyghambarzadeh S.M., Hashemabadi S.H., Hoseini S.M., Seifi M.: Experimental study of heat transfer enhancement using water/ethylene glycol based nanofluids as a new coolant for car radiators. Int. Comm. Heat Mass Transfer 38(2011), 1283-1290.
 Lee S.S., Choi U.S., Li S.,Eastman J.A.: Measuring thermal conductivity of fluids containing oxide nanoparticles. J. Heat Trans. 121(1999), 2, 280-289.
 Naraki M., Peyghambarzadeh S.M., Hashemabadi S.H., Vermahmoudi Y.: Parametric study of overal l heat transfer coefficient of CuO/water nanofluids in a car radiator. Int. J. Therm. Sci. 66(2013), 66, 82-90.
 Peyghambarzadeh S.M., Hashemabadi S.H., Naraki M., Vermahmoudi Y.: Experimental study of overal l heat transfer coefficient in the application of dilute nanofluids in the car radiator. Appl. Therm. Eng. 52(2013), 8-16.
 Wang X.Q., Mujumdar A.S.: Heat transfer characteristics of nanofluids.a review. Int. J. Therm. Sci. 46(2007), 1, 1-19.
 Eastman J.A., Choi U.S., Li S., Thompson L.J., Lee S.: Enhanced thermal conductivity through the development of nanofluids. Mater. Res. Soc. Symp. Proc., Cambridge Univ. Press (1997).
 Wang X., Xu X., Choi S.U.S.: Thermal conductivity of nanoparticle-fluid mixture. J. Thermophys. Heat Transfer 13(1999), 4, 474-480.
 Masuda H., Ebata A., Teramae K., Hishinuma N.: Alteration of thermal conductivity and viscosity of liquid by dispersing ultra-fine particles. Netsu Bussei 7(1993), 2, 227-233.
 Keshavarz M., Darabi M., Hossein Haddad S.M., Davarnejad R.: Modeling of convective heat transfer of a nanofluid in the developing region of tube flow with computational fluid dynamics. Int. Comm. Heat Mass Trans. 38(2011), 1291-1295.
 Demir H., Dalkilic A.S., Kurekci N.A., Duangthongsuk W., Wongwises S.: Numerical investigation on the single phase forced convection heat transfer characteristics of TiO2 nanofluids in a double-tube counter flow heat exchanger. Int. Comm. Heat Mass Trans. 38(2011), 218-228.
 Das S.K., Putra N., Roetzel W.: Pool boiling characteristics of nano-fluids. Int. Comm. Heat Mass Transfer 46(2003), 851-862.
 Patankar S.V., Pratap V.S., Spalding D.B.: Prediction of turbulent flow in curved pipes. J. Fluid Mech. 67(1975), 583-595.
 Pak B.C., Cho Y.I.: Hydrodynamic and heat transfer study of dispersed fluids with submicron metallic oxide particles. Experimental Heat Transfer: J. Therm. Energ. Gener. Transp. Stor. Conver. 11(1998), 151-170.
 Koo J., Kleinstreuer C.: A new thermal conductivity model for nanofluids. J. Nanoparticle Res. 6(2004), 577-588.
 Batchelor G.K.: The effect of Brownian motion on the bulk stress in a suspension of spherical particles. J. Fluid Mech. 83(1977), 1, 97-117.
 Xuan Y., Roetzel W.: Conceptions of heat transfer correlation of nanofluids. Int. J. Heat Mass Trans. 43(2000), 3701-3707.
 Hamilton R.L., Crosser O.K.: Thermal Conductivity of Heterogeneous Two- Component Systems. Ind. Eng. Chem. Fund. 3(1962), 187-191.
 Turgut A., Tavman I., Chirtoc M., Schuchmann H.P., C. Sauter, Tavman S.: Thermal conductivity and viscosity measurements of water based TiO2 nanofluids. Int. J. Thermophys. 30(2009), 1213-1226.
 Yu W., Choi S.U.S.: The role of interfacial layers in the enhanced thermal conductivity of nanofluids; a renovated Maxwell model. J. Nanoparticle Res. 5(2003), 167-171.
 Bejan A.: A study of entropy generation in fundamental convective heat transfer. J. Heat Trans. ASME 101(1979), 718-725.
 Bejan A.: Entropy Generation through Heat and Fluid Flow. Willy & Sons, 1982.
 Qasim Saleh Mahdi, Sahar A. Fattah, AbboodFiras A. Abbas.: Investigation of heat transfer from U-longitudinal finned tube heat exchanger. Adv. Energ. Power 3(2015), 19-28.