The heat transfer and fluid flow characteristics of water/Fe3O4 ferrofluid flow in a tube with V-cut twisted tape turbulator under the magnetic field effect

Abstract

The magnetic field (MF) effect on the heat transfer of Fe3O4 ferrofluid swirl flow inside a tube with turbulator was investigated under three Re numbers (200, 400, and 600), turbulator pitches (H = 50 mm, 100 mm, and 150 mm), and three scenarios of MF location. The outputs demonstrated that by applying the MF on zone#1 (near the entrance), zone#2 (middle of tube), and zone#3 (near the outlet) improves convective heat transfer coefficient (h) over the tube without MF by 1.1% (or 2.49%), 11.13% (or 14.94%), and 39.42% (or 10.91%), respectively, at Re of 200 (or 600). In consequence, the absorber tube temperature reduces by 0.207% (or 2.23%), 0.058% (or 0.498%), and 0.068% (or 0.293%), respectively, for zones 1, 2, and 3 and at Re = 200 (or 600). In addition, the MF increases the pressure drop over the tube without MF by nearly 16%, 9%, and 4%, for zones 1, 2, and 3, respectively. Furthermore, the intensification of H from 50 mm to 150 mm at Res of 200–600 decreased h by 30.21–19.32% and 28.51–26.91% under zone#1 and zone#2 scenarios, respectively, while enhanced that by 5.52–0.26% for MF applied on zone#3. Furthermore, the highest PEC was obtained as 1.55–2.36 for H values of 50 mm-150 mm when MF is applied on zone#3 and at Re = 200.