Denis Funfschilling

A benchmark study on the thermal conductivity of nanofluids

This article reports on the International Nanofluid Property Benchmark Exercise, or INPBE, in which the thermal conductivity of identical samples of colloidally stable dispersions of nanoparticles or “nanofluids,” was measured by over 30 organizations worldwide, using a variety of experimental approaches, including the transient hot wire method, steady-state methods, and optical methods. The nanofluids tested in the exercise were comprised of aqueous and nonaqueous basefluids, metal and metal oxide particles, near-spherical and elongated particles, at low and high particle concentrations. The data analysis reveals that the data from most organizations lie within a relatively narrow band (±10% or less) about the sample average with only few outliers. The thermal conductivity of the nanofluids was found to increase with particle concentration and aspect ratio, as expected from classical theory. There are (small) systematic differences in the absolute values of the nanofluid thermal conductivity among the various experimental approaches; however, such differences tend to disappear when the data are normalized to the measured thermal conductivity of the basefluid. The effective medium theory developed for dispersed particles by Maxwell in 1881 and recently generalized by Nan et al. [J. Appl. Phys. 81, 6692 (1997)], was found to be in good agreement with the experimental data, suggesting that no anomalous enhancement of thermal conductivity was achieved in the nanofluids tested in this exercise.

Heat transport by turbulent Rayleigh–Bénard convection in cylindrical cells with aspect ratio one and less

We present high-precision measurements of the Nusselt number

Non-Oberbeck–Boussinesq effects in strongly turbulent Rayleigh–Bénard convection

\cal N

Heat transport in turbulent Rayleigh-Bénard convection: Effect of finite top- and bottom-plate conductivities

as a function of the Rayleigh number

Flow of non-Newtonian fluids around bubbles: PIV measurements and birefringence visualisation

R

Logarithmic temperature profiles in turbulent Rayleigh-Bénard convection

for cylindrical samples of water (Prandtl number

Towards the understanding of bubble interactions and coalescence in non-Newtonian fluids: a cognitive approach

\sigma \,{=}\, 4.4

Torsional oscillations of the large-scale circulation in turbulent Rayleigh–Bénard convection

) with a diameter

Effects of shear rate and temperature on viscosity of alumina polyalphaolefins nanofluids

D

Bubbles in a viscous liquid: lattice Boltzmann simulation and experimental validation

of 49.7 cm and heights