A Review on Properties, Opportunities, and Challenges of Transformer Oil-Based Nanofluids

Table 9

Enhancement of thermal conductivity.

Author/year	Nanofluid	Particle size (nm)	Concentration (vol%)	Enhancement ratio
Choi et al./2008 [39]	Cu/transformer oil	100	2.50–7.50	1.12–1.43
Choi et al./2008 [39]	Al2O3 (sphere)/pure oil	13	0.5–4.0	1.05–1.21
	Al2O3 (fiber)/pure oil	–200	0.5	1.04
	AlN/pure oil	50	0.5	1.08