Some researchers argue that the anomalous k enhancement data, for nanofluids, is caused by inaccuracies of thermal measurement methods. In this paper, measurements on thermal conductivities of nanofluid mixtures (alumina/water) by means of two different methods are accomplished. The thermal conductivity was measured, and through the laser flash method, with the NETZSCH LFA 447 NanoFlash. Five samples of nanofluid, with varying alumina concentration was tested (0.1%, 0.5%, 2.0%, 3.0%, and 4.0%). The deviations between the ...
The purpose of this study was to measure the thermodynamic properties of 1-hexyl-3-methylimidazolium tetrafluoroborate ([HMIM]BF4) and its graphene-dispersed ionic liquid based nanofluids (Ionanofluids) from room temperature to 200 °C. A thermal analyzer measured the thermal conductivity of the samples using the transient plane source (TPS) method. Results showed that the thermal conductivity of [HMIM]BF4 and the GE-dispersed Ionanofluids increased linearly with temperature, and with mass particle fraction. It ...
Enhancing heat transfer in miniaturized radiators is an important goal for many researchers. In this study, silver nanofluids were employed to improve the transfer of heat in micro-pin fin heat sinks. A thermal constant analyzer measured the thermal conductivity of the silver nanofluid samples using the transient plane source (TPS) technique. Results showed that the addition of silver nanoparticles to the working fluids improved thermal conductivity, but at high concentrations, ...
One way to increase the thermal conductivity of a conventional fluid is to add solid particles to the liquid. Aluminum nitride (AlN) is an effective thermal conductor so it is popularly used to fabricate nanofluids. In this study, 20 nanometer particles of AlN were distributed into ethanol and the thermal conductivity of the solution was measured using a thermal constant analyzer from 0.5 volume fraction (vol%) to 4.0 vol% at 273.15 kelvin (K) and 297.15 ...
In an effort to enhance heat transfer in the laminar flow regime of a heating duct, TiO2 and SiO2 nanoparticles were added to water to create nanofluids with a higher thermal conductivity than that of the water alone. Twist-tape was also used to enhance heat transfer within the duct. The thermal conductivities of the nanofluids were measured using the Transient Plane Source instrument. It was found that the use of ...
