Develop Boltzmann equation to simulate non-Newtonian magneto-hydrodynamic nanofluid flow using power law magnetic Reynolds number

The single relaxation D2Q9 lattice Boltzmann method (LBM) is run in the current research beside the generalized power law model for simulation of non‐Newtonian magneto‐hydrodynamics (MHD) laminar flow field inside a channel with local symmetric constriction. Analytical results of non‐Newtonian fluid flow in a channel without magnetic field, as well as Newtonian fluid flow at various Hartmann No., are used to validate the numerical model. Then, fluid flow simulation is performed for non‐Newtonian fluid with different power law index at various Hartmann No. (Ha ) whereas Reynolds No. are set to be constant in all cases. The present non‐Newtonian fluid can be achieved by adding various nanoparticles such as MWCNT to the base fluid. To explore the effect of magnetic Reynolds No. (Re m ), the fluid flows with different magnetic resistivity are also simulated. Results show that the separation can be controlled by a magnetic field with the penalty of larger friction coefficient and pressure loss along the channel length. In fact, for a specified Re m , the higher the Ha , the larger the pressure loss. It is also observed that the pressure loss is larger for fluids flow with higher power law index and lower Re_m

Thermal conductivity enhancement of nanofluid by adding multiwalled carbon nanotubes: Characterization and numerical modeling patterns

© 2020 John Wiley & Sons, Ltd. Nanofluid is divided in two major section, mono nanofluid (MN) and hybrid nanofluid (HN). MN is created when a solid nanoparticle disperses in a fluid, whereas HN has more than one solid nanomaterial. In this research, iron (III) oxide (Fe3O4) is MN, and Fe3O4 plus multiwalled carbon nanotube (MWCNT) is HN, whereas both are mixed and dispersed into the water basefluid. Thermal conductivity (TC) of Fe3O4/water and MWCNT/Fe3O4/water was measured after preparation and numerical model performed on the resulted data. After that, field emission scanning electron microscope (FESEM) was studied for microstructural observation of nanoparticles. MN and HN TC were studied at temperature ranges of 25 to 50°C and volume fractions of 0.2% to 1.0%. For MN and HN, thermal conductivity enhancement (TCE) of 32.76% and 33.23% was measured at 50°C temperature—1.0% volume fraction, individually. Different correlations have been calculated for numerical modeling, with R2 = 0.9. Deviation of 0.6007% and 0.6096% was calculated for given correlations for MN and HN individually. Deviation of 0.5862% and 0.6057% was calculated for trained models, for MN and HN individually. Thus, by adding MWCNT to Fe3O4-H2O nanofluid, TC is enhanced 0.47%, and this HN has agreeable heat transfer potential