Experimental heat transfer, friction factor and effectiveness analysis of Fe3O4 nanofluid flow in a horizontal plain tube with return bend and wire coil inserts

The paper reports on the convective heat transfer, friction factor, effectiveness and number of transfer units (NTU) of Fe3O4/water nanofluids flow in a double pipe U-bend heat exchanger with and without wire coil inserts under turbulent flow conditions. The heat transfer and friction factor experiments were conducted at different Reynolds numbers (16,000–30,000), different particle concentrations (0.005–0.06%) and different wire coil inserts of...