Passive cooling is a method of dissipating heat rejected by electronic devices, and when associated to a phase change can be very effective. Phase change materials (PCMs) are widely used for thermal storage applications due to their ability to store and release large amounts of energy. Paraffin waxes also exhibit desirable characteristics, such as high latent heat and low thermal conductivity. This article looks at four nano-PCMs, obtained by seeding ...
In 1967, Gustafsson proposed the idea of the transient plane source (TPS) method, but it was not developed until the 1990’s with the help of Gustavsson. The TPS method uses an engraved spiral nickel sensor to simultaneously administer a heat conducting current while measuring the temperature increase of the sample over the time. Transient plane source methods are popular because there is no limit to the sample size, the thermal range ...
Phase change materials (PCMs) are substances that release large amounts of energy in the form of latent heat when they freeze. Paraffin waxes have many of the desired characteristics PCMs exhibit except that they have low thermal conductivity. In this experiment, Alumina and Carbon Black nanoparticles were added to two types of paraffin waxes (melting points of 20-25 °C) to increase their thermal conductivity. A Transient Plane Source (TPS) measured ...
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 ...
This article looks at the thermal properties of titanium oxide (TiO2) based nanofluids and their applications as thermal vectors. The nanoparticle size was studied by dynamic light scattering (DLS) and the stability was measured by Zeta potential. The concentrations of TiO2 used ranged from 1 to 35% by mass in the water-based nanofluid. Thermal conductivity was measured and the effects of concentration of TiO2 and temperature on the thermal conductivity were studied. ...
