Physical-Statistical Model of Thermal Conductivity of Nanofluids

Table 1

Values and expressions for parameters used in calculating the 𝑘 of medium (^b𝑇 in °C).

Source	Thermal conductivity; Parameters (W m^−1 K^−1)	Expression, value^b
[2]	Al2O3, 𝑘np,	40
[2]	CuO, 𝑘np,	32.9
[2]	TiO2, 𝑘np	8.4
[2]	ethylene glycol, 𝑘𝑓,	0.253
[13]	Water, 𝑘𝑓,	0.552+2.3410^−3𝑇−1.1⋅10^−5𝑇^2
[13]	air, 𝑘𝑔,	0.0237+0.000064𝑇
[12]	Brownian motion, 𝑘bm,	𝑘bm=12𝜌cp𝑐𝑝−cp𝑑𝑠3𝐾𝐵𝑇1−1.5𝛾^3𝜙𝑝2𝜋𝜌cp𝛾^3𝑟^3𝑝

Where: 𝑑_𝑠=0.893𝑟_cp𝜙^−1/3_cp=0.893𝑟_𝑝𝜙_𝑝^−1/3, 𝜌_cp and 𝑐_𝑝−cp are the density and specific heat of complex nanoparticles, 𝜙_𝑝—the particle volume fraction, 𝐾_𝐵 is the Boltzmann’s constant, 𝛾=1+ℎ/𝑟_𝑝, 𝑟_𝑝 is the radius of nanoparticle, ℎ is the interfacial layer of thickness and the fluid medium, 𝑇—temperature, respectively.