Table 1.

Typical nanofluid viscosity prediction models.

Researcher	Year	Model	R2	Remarks
Einstein63	1906	μs = μbf(1 + 2.5φ)	0.501	For rigid solid spheres, the volume fraction <2%
Batchelor64	1977	μs = μbf(1 + 2.5φ + 6.2φ2)	0.5312	Interactions between particles was considered, a very low concentration
Wang et al.65	1999	μs = μbf(1 + 7.3φ + 123φ2)	0.8351	Empirical generic model
This study	2017	μs = μbf(1 + 117φ − 269.8φ2 + 229.6φ3)	0.9972	Empirical model