Analysis of empirical correlations of thermophysical properties of water suspensions of aluminum oxide nanoparticles
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DOI: 10.1134/S0869864320020018
Analysis of empirical correlations of thermophysical properties of water suspensions of aluminum oxide nanoparticles A.A. Fomin1 and L.N. Fomina2 1
T.F. Gorbachev Kuzbass State Technical University, Kemerovo, Russia
2
Kemerovo State University, Kemerovo, Russia
E-mail: [email protected] (Received May 7, 2019; revised October 25, 2019; accepted for publication November 6, 2019) Here, we consider the empirical relationships presented earlier in the literature that describe the thermophysical properties of H2O + Al2O3 nanofluids, such as viscosity and heat conductivity coefficients. The main parameters affecting these properties of nanofluid are considered to be the volume fraction of particles ϕ, fluid temperature T, and particle size dp. The suitability of approximation formulas for calculating the viscosity and heat conductivity coefficients is determined by comparing the data calculated by these formulas with the experimental results. The behavior of the analytical curves of thermophysical coefficients is analyzed in the following ranges of influencing parameters: 0 < ϕ ≤ 0.1, 280 K ≤ Т ≤ 360 K, 1 nm ≤ dp ≤ 100 nm. Estimates of the degree of dependence of calculation results on the values of these parameters are given. Conclusions on the qualitative and quantitative reliability of the correlation formulas proposed in the literature, as well as on the limits of their applicability in the ranges of variation of the influencing parameters are drawn. Keywords: nanofluid, viscosity, heat conductivity, correlation relations, comparative analysis.
Introduction Recently, scientific studies related to the study and modeling of the thermophysical properties of nanofluids, such as viscosity and heat conductivity coefficients, have become widespread. The term “nanofluid” itself was first proposed apparently in [1] and it means a colloidal solution of nanosized particles in a base fluid. It is known that the addition of a small amount of such particles (several percents by volume) to the carrier fluid can dramatically increase the effective heat conductivity of solution [2]. In this regard, there are great prospects for the practical application of nanofluids, primarily in technical devices subject to intense heating. Therefore, scientific works dealing with modeling the thermophysical properties of nanofluids have a high level of relevance. Reviews of the studies can be found, for example, in [2–6]. However, despite a significant number of publications, the work in this direction is far from completion. In this sense, review [4], which, in particular, includes the tables of significant improvements in heat conductivity of nanofluids with respect to base fluids in the form of A.A. Fomin and L.N. Fomina, 2020
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A.A. Fomin and L.N. Fomina
a summary of numerous experimental works, is very indicative. The research results have been structured according to the type of nanofluids, the ranges of flow temperatures, and the flow regimes (laminar/turbulent). A comparative analysis of experimen
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