ISSN Online: 2688-7231
ISBN Online: 978-1-56700-524-0
Proceedings of the 26thNational and 4th International ISHMT-ASTFE Heat and Mass Transfer Conference December 17-20, 2021, IIT Madras, Chennai-600036, Tamil Nadu, India
Experimental setup to measure thermal diffusivity of solid rod sample using Ångström method at different temperatures
Thermal diffusivity of a material is a measure of the rate at which heat propagates through it. This is related to other thermal properties such as thermal conductivity, specific heat and density. This paper describes an in-house developed experimental setup which can measure thermal diffusivity of solid rod material for temperature range from room temperature (RT) to 122° C using the thermal wave based Ångstrom method. In this technique, a periodic heat load is supplied to one end of the sample and temperatures are measured at different locations along the sample. Thermal diffusivity is estimated from the measured phase shift of temperature oscillations and temperature amplitudes along the specimen. One of the key features of this technique is that the thermal diffusivity result is independent of the heat transfer coefficient with the surroundings and is therefore independent of environmental condition. The experiments were performed on Stainless steel (SS316) and Aluminum alloy (A6061-T6) samples with sinusoidal heat inputs. For Al6061-T6 sample, test was conducted for the temperature range room temperature (RT) to 122 °C. The obtained experimental data were Fourier analyzed using a MATLAB code. The results indicate that the thermal diffusivity deviates from the literature value at room temperature by less than 5%. Further, for validation purpose, thermal diffusivity obtained experimentally with this method were compared with the measurement results obtained from a standard thermal diffusivity instrument Flashline-5000 based on flash method over the stated temperature range. The result indicates that in measured temperature range thermal diffusivity obtained by the in-house developed Ångström based setup deviates from flash based standard instrument by less than 1%. Thus, the in-house developed setup gives results that are comparable with standard instrument.