The influence of magneto-hydrodynamics and vortex generators on nanofluids heat transfer

Abstract

This paper investigates the effects of a vortex generator (VG) and magneto-hydrodynamics (MHD) on the thermal properties of nanofluids in a microchannel. A variety of test scenarios within the laminar flow regimes are numerically examined: nanofluids in a hot-walled simple channel (SC); nanofluids in a heated-walled channel where a circular cylinder is embedded within the channel and functions as a vortex generator (VG); nanofluids in a heated-walled channel that incorporates both a vortex generator and magneto-hydrodynamics (VG-MHD). The channel has a circular cylinder with a diameter of D that is fixed inside the channel with various gap ratios (GR = G/D) ranging from 0.5 to 4.0. Numerical investigations for laminar flow with Re ≤ 1,000 are carried out. The nanoparticle volume fractions range from 0 % to 7 %, and the magnetic field is set at 0.05 T. The best heat transmission conditions with the lowest skin friction coefficient are evaluated for the optimal GR. It is found that heat transfer is enhanced by approximately 20 % when MHD and VG effects are employed, in contrast to a traditional channel that does not utilize the MHD effect.