Nanofluids Research: Key Issues

Table 1 Measured conductivity ratio k/k _b of some nanofluids (k: nanofluid thermal conductivity; k _b: base-fluid thermal conductivity)

Nanofluids	k/k _b
CePO₄ nanofibers in water [28, 32]	0.67–1.54
Cu₂O spherical particles in water [31]	0.83–1.24
Cu₂O octahedral particles in water [31]	0.89–1.24
CuS/Cu₂S hollow spherical particles in water [30]	0.85–1.18
CuS/Cu₂S core–shell spherical particles in water [30]	0.82–1.21
1 vol% Alumina nanorods (80 × 10 nm) in water [67]	0.92–1.18
1 vol% Alumina nanorods (80 × 10 nm) in Polyalphaolefins lubricant (PAO) + surfactant [67]	0.91–1.10
0.001 vol% Gold nanoparticles (20–30 nm) in water [67]	0.91–1.11
0.86 vol% Mn–Zn ferrite (12.9 nm) in water [67]	0.92–1.09
Corn oil droplets in water [74]	0.755–2.39
Olive oil droplets in water [28]	0.636–2.533