Ahmad Azari - Department of Chemical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Mahshahr Branch, Iran
Mansour Kalbasi - Department of Chemical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Mahshahr Branch, Iran
Masoud Rahimi - CFD Research Center, Chemical Engineering Department, Razi University, Taghe Bostan, Kermanshah, Iran

This paper reports Computational Fluid Dynamics (CFD) investigations on the Nusselt number and heat transfer performance of Al2O3/Water nanofluids under laminar flow condition in circular tube submitted to a constant and uniform heat flux at the wall. A single-phase model is employedwith either constant or temperature dependent properties. The investigation is accomplished for size particles equal to 50 nm. Convective heat transfer coefficient for nanofluids is greater than that of the base liquid and heat transfer enhancement increases with the particle volumeconcentration. Higher heat transfer coefficients are detected in the case of temperature dependentsmodel and the heat transfer always improves, as Reynolds number increases. Moreover acomparison with the experimental data present in the literature is carried out and good conformity between the model predictions and the experimental data is achived

Nanofluids, Nusselt number, heat transfer coefficient, single-phase model, constant and variable property