Effect of magnetic field on the thermophysical properties of low-density ferrofluid with disk-shaped MgFe2O4 nanoparticles

Correlating the Dipolar Interactions Induced Magneto‐Viscoelasticity and Thermal Conductivity Enhancements in Nanomagnetic Fluids

“…Figure 18b illustrates the relationship between the TC of water‐based magnesium ferrite (MgFe 2 O 4 ) NMFs and the volume fraction of NPs in the presence of magnetic field. [ 217 ] The findings indicate that an increase in the quantity of MgFe 2 O 4 NPs led to an improvement in the TC of NMF. When compared to DI water, the maximum increase in TC of MgFe 2 O 4 based NMFs was 10.06% at a volume fraction of 0.20% in the absence of magnetic field.…”

“…[37,39,66] The anomalous thermal conductivity is observed when an external magnetic field is present, which may be influenced by the direction and strength of the applied magnetic field, and has been the focus of recent research on the regulation of TC in NMFs. [20,217,218,59] The gradual transformation of chains into thick columnar structures in the presence of the applied magnetic field enhances TC and viscosity of the NMFs. The enhancement in TC under the influence of magnetic field arises because of the alignment of magnetic moments of the MNPs that are dispersed in the carrier fluids due to the chain cluster formation.…”

“…Weight fraction Enhancement in TC Reported By Factors Enhancing TC 0.65-0.83 0.5-4.8% 196% (A. Karimi2014) et al [ 249] Field induced chain like structures 0.58-0.67 3% 11.4% (Abreshi2010) et al [ 251] Volume fraction 0.65-0.97 0-2% 8.37-48% (S. Sundar2013) et al [ 261] Operating temperature and volume fraction 0.9 7% 106-284% (A. Katiyar2016) et al [ 250] Morphology and composition -10% 173% (Mercedes Arana 2017) et al [ 260] Nanoaggregates formation 0.60-0.75 0.25-3% 26.4-36.5% (Mohammad 2017) et al [97] Volume fraction and temperature 0.19 -71% (O. Madalin2019) et al [ 255] Formation of particle agglomerations of the form of elongated droplets 0.26-0.30 0.01-0.25% 13.3-95.6% (N. Keklikcioglu2020) et al [95] Operating temperature and volume fraction 0.14-0.16 0.005-0.03% 17-28.57% (Y. Zheng2020) et al [ 254] Volume fraction 0.45 0.01-0.1% 9.5-14.3% (A. Banisharif2020) et al [ 257] Brownian motion of nanoparticles 0.68 0.0-0.2% 13.92% (k. Ajith2021) wt al. [ 217] Volume fraction…”

Effect of the non-electrically conductive spindle on the viscosity measurements of nanofluids subjected to the magnetic field

“…The selection of nanoparticles is related to the application of interest in which a low-density NF is necessary to improve buoyancy and enhance the natural convection process. MgFe2O4 nanoparticles are synthesized by hydrothermal method [38,39] and the morphology is analyzed using TEM. The TEM analysis presented in Fig.…”

Effect of ferrofluid magnetization on transformer temperature rise

“…Then, in addition to the thermal conductivity increase due to the Brownian motion and collisions of magnetic nanoparticles possibly leading to the chain-like particle networking [22], the magnetic field-induced particle assembly in ferrofluids also enhances the total heat transfer significantly. For instance, the thermal conductivity of magnesium ferrite ferrofluid raised by 10.06% in the absence of the magnetic field, but a 13.92% increase was found in the presence of the magnetic field (350 G) [23]. The presence of a magnetic field gradient can introduce a magnetic body force on the ferrofluid flow, resulting in enhanced convective heat transfer.…”