Measurement of Thermo Physical Properties of Metallic Nanofluids for High Temperature Applications

Effect of volume concentration and temperature on viscosity and surface tension of graphene–water nanofluid for heat transfer applications

“…It was already investigated by the present authors [4] that the thermal conductivity and viscosity values of Ag-water nanofluids at higher temperatures did not agree and showed a large deviation against well-known thermal conductivity and viscosity models. Hence, the effectiveness of nanofluids should be evaluated for using it as a heat transfer fluid in the real-time thermal systems.…”

“…A fluid with enhanced heat transfer properties can solve this issue to an extent. The thermal and heat transfer properties of the conventional cooling fluids are enhanced by suspending nanometer-sized (1-100 nm) solid particles with higher thermal conductivity and high surface area, resulting in a two-phase mixture called a nanofluid [4][5][6]. Nowadays, nanofluids are widely used in a variety of applications, such as electronic cooling, internal combustion engine cooling and lubrication, industrial cooling, industrial and comfort air conditioning and extraction of geothermal and solar energy [7,8] due to its enhanced thermal properties [9][10][11][12][13].…”

β-Zn4Sb3Nanocantilevers and Their Thermoelectric Properties

“…To verify the reproducibility of the low thermal conductivity in nanostructures, multiple samples were prepared in different batches, and consistently low values, ranging from 0.58 to 0.98 W/m•K at room temperature, were routinely recorded. The conductivities k (Figure 3a) of the as-obtained nanocantilevers and conventional powders were very low (0.58 and 0.98 W/K m at 300 K, respectively), in which they decreased with increasing temperature (0.37 and 0.43 W/K m at 675 K, respectively) and minimized the thermal conductivity possible from promoting phonon scattering and localization [45][46][47][48][49][50]. The Seebeck coefficient S and electrical conductivity σ are presented in Figures 3b and 3c, respectively, in which the Seebeck coefficients of all samples are positive and a weak semimetal temperature behavior can be seen.…”

“…As an earlier report [43], β-Zn 4 Sb 3 was found to be stable when heated to high temperatures since Zn 3 Sb 2 failed to form. It can be seen that the thermal conductivity of the nanocantilevers is comparable to that of conventional powders [43][44][45][46][47][48][49][50]. To verify the reproducibility of the low thermal conductivity in nanostructures, multiple samples were prepared in different batches, and consistently low values, ranging from 0.58 to 0.98 W/m•K at room temperature, were routinely recorded.…”

Nanofluids for Heat Transfer – Potential and Engineering Strategies

“…Metallic nanofluids are less investigated than ceramic nanofluids because of the limited oxidative stability of many affordable metals and high cost of chemically stable precious metal nanoparticles. However many experimental results for metallic nanofluids report thermal conductivity increases well above the effective medium theory prediction [36][37][38][39][40][41][42][43][44] as summarized in Figure 1. Data from different research groups are quite scattered, possibly because of the difference in the preparation techniques, particle size, material, base fluids, surfactants, and also uncertainties in measurements of particle concentration and thermal conductivity [3].…”