Numerical investigation on turbulent convective heat transfer of nanofluid flow in a square cross-sectioned duct

The purpose of this study is to numerically investigate the heat transfer enhancement by using two different nanofluids flow throughout the square duct under a constant heat flux (500 × 10³ W/m²).

In numerical computations, ANSYS Fluent code based on the finite volume method was used to solve governing equations by iteratively. Water, Al₂O₃-water and TiO₂-water nanofluids were used for different flow velocities changing 1 m/s to 8 m/s (i.e. Reynolds number varying from 3,000 to 100,000).

The results were compared with results published previously in the literature and close agreement was observed especially considering Dittus and Boelter correlation for water. It was found that from the obtained results, increasing flow velocity and volume fractions of nanoparticles has caused to increase Nu number for all cases. Besides, variations of pressure drop, Darcy friction factor are presented graphically and discussed in detail. The results are consistent with a deviation of 1.3 to 15 per cent with the results of other researchers.

The effects of the Re numbers and volume fractions of nanoparticles (0.01 ≤ Φ ≤ 0.04) on the heat transfer and fluid flow characteristics such as average Nu number, pressure drop (ΔP) and Darcy friction factor (f) were investigated.