Proposed new equations for calculation of thermophysical properties of nanofluids

Abstract

A trial-error procedure is applied for the derivation of correlations to estimate the relative thermalconductivity (kr) and dynamic viscosity (µr) of nanofluids using MATLAB. Thermophysicalproperties of particles and base fluids, particle diameter (dp), sphericity, capping layer thickness,Brownian motion of a particle, temperature, and volume fraction (?) are considered. The accuracyof predicting kr and µr of nanofluids is developed using dimensionless parameters involving basefluid and particle characteristics. The results reveal that the estimated values are in a goodagreement with the experimental data with a standard deviation of 2.16% and 8.16% for kr and µrof nanofluids, respectively. Besides that, 97.5% of the predicted kr values suit experimental dataof kr with a mean deviation of ±5%, whereas 90.4% of the estimated µr values match the data ofµr with a mean deviation of ±10%. Therefore, the proposed new equations will be useful fornumerical simulation studies and the engineering design of heat transfer devices such asrefrigeration systems, solar collectors, and heat exchangers.