CFD modeling of laminar flow and heat transfer utilizing Al 2 O 3 /water nanofluid in a finned-tube with twisted tape

Abstract

This study investigates numerically heat transfer augmentation using water-based Al 2 O 3 nanofluid flowing in a circular cross-sectional tube under constant inlet temperature in laminar flow conditions. The Al 2 O 3 /water nanofluid with different volume fractions (3% and 5%) and twisted tape twist ratio of (H/D =1.85) are employed, and Reynolds numbers of 678 to 2033 in a laminar flow are considered. The numerical analysis is used to solve the governing partial differential equations in three dimensions. Results of the flow structure, velocity vector, and temperature field are reported. The numerical results indicate that the heat transfer rate becomes more remarkable when employing nanofluid. The maximum 46% enhancement is obtained in the convective heat transfer coefficient by using Al 2 O 3 /water nanofluid at 5% particle volume fraction and Reynolds number of 678, comparing with pure water. It is also found that heat transfer enhancement increases with an increase in the particle volume concentration and Reynolds number.