Acoustic Method for Determination of the Thermal Properties of Nanofluids

Abstract

This study determines the thermophysical properties of nanofluids using ultrasonic techniques. Using an acoustic test cell, fitted with 4 MHz high-temperature transducers, measurements of the speed of sound in an aqueous dispersion of alumina nanoparticles (Al2O3, 99.9%, spherical, dp = 50 nm) are made at volume fractions from 1-5 vol% over the temperature range 20-90°C. The observed relationships between the measured parameters and speed of sound variation are presented. Available theoretical approaches are reviewed and applied to the data of the study. The speed of sound data together with measurements of density and predictions of thermal conductivity, derived from Lagrangian particle tracking (LPT) simulations, are used to determine

Modeling photoacoustic pressure generation in colloidal suspensions at different volume fractions based on a multi-scale approach

“…The WB and Urick models rely on the mixing rule for the dispersed particle phase and base fluid phase. The numerical results using the two models agree with experimental results at different volume fractions up to roughly 20% for the specific heat capacity [19] and 5% for the sound velocity [21] . Because the two models consider no interaction between colloidal particles, the agreements indicate less influences of the particle interaction on the thermodynamic properties at the volume fraction ranges.…”

“…We adopted the particle size distributions of silica measured by Horváth-Szabó and Høiland (mean value of 83 nm) [41] and alumina by Mahmoud et al. [21] (mean value of 55 nm), respectively. Please see the references, including our previous work, for the explicit formulations of the IST and DST and numerical conditions [27] , [36] .…”

Numerical Study of Near-Infrared Light Propagation in Aqueous Alumina Suspensions Using the Steady-State Radiative Transfer Equation and Dependent Scattering Theory

“…We considered aqueous alumina suspensions as a size-polydisperse colloidal suspension. We used the particle size distribution of an alumina suspension after sonification measured by Mahmoud et al [49]. Figure 3 shows the fraction of particle size with the mean diameter d mean of 55 nm and N d = 10.…”