Transient methods are often preferred to steady-state methods when testing the thermophysical properties of materials because of they are simple to use, can quickly produce measurements, and can simultaneously test three thermal properties. There are two factors that influence the accuracy of contact transient testing that must be accounted for when developing a standard: measurement time, and the geometry of the sample and the sensor. To demonstrate this point, when ...
The transient technique is the commercial method used to test the thermal conductivity, thermal diffusivity, and specific heat of solids. With the instrument, a double spiral nickel sensor is sandwiched between two homogenous samples, and as the sensor pulses electrical currents through the sample, it simultaneously measures how long it takes for the temperature of the sample to increase. This method is typically used on glasses, insulating materials, and polymer ...
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 ...
The Transient Plane Source (TPS) Technique measures the thermal conductivity, thermal diffusivity, and specific heat of solids and liquids. An electrically conducting double spiral nickel sensor pulses a current through a sample which increases its temperature, while simultaneously recording the length of time it took for the sample to heat up. This study, researchers tested the thermal properties of various materials and determined that anisotropy must be considered when these ...
In this study, loop heat pipe capillary wicks were prepared and the transient plane source (TPS) method measured the thermal conductivity, thermal diffusivity, and specific heat of the samples. The results showed that thermal conductivity increased with porosity, but porosity seemingly had no effect on diffusivity and specific heat....
