An experimental study on the cooling efficiency of magnetite-water nanofluid in a twisted tube exposed to a rotating magnetic field

In this experimental research, the laminar forced convection of water-magnetite nanofluid (NF) in a horizontal twisted tube (TT) is examined under a rotating magnetic field (MF). The findings are compared with those of the plain tube (PT). The influence of nanoadditive concentration (phi), Reynolds number (Re), twist pitch (P) and MF arrangement on the heat transfer, friction factor and overall thermohydraulic features of NF is assessed. The MF consists of two magnets that rotate around the tube. For each of the magnets, three modes of clockwise rotation, counterclockwise rotation and without rotation are considered. The findings showed that the combined use of TT and rotating MF entails an increase in the overall thermohydraulic features of water-magnetite NF. In addition, it was found that the overall thermohydraulic features of NF augment with boosting phi, while they decline with boostingPand Re. Moreover, it was revealed that the best thermohydraulic features of the water-magnetite NF belonged to the case of phi = 2%, Re = 500 andP = 10 mm in the presence of a rotating magnetic field resulting from the clockwise rotation of the first magnet and the counterclockwise rotation of the second magnet.

Automated summary

Experimental research showed that the combined use of a twisted tube and a rotating magnetic field enhances the overall thermohydraulic features of water-magnetite nanofluid. The best overall thermohydraulic features were observed in the case of nanoadditive concentration at 2%, Reynolds number at 500, and twist pitch at 10 mm, with a rotating magnetic field resulting from clockwise rotation of the first magnet and counterclockwise rotation of the second magnet.