Arrag Tragangoon. Thermal diffusivity measurement of porous materials. Master's Degree(Mechanical Engineering). King Mongkut's University of Technology North Bangkok. Central Library. : King Mongkut's University of Technology North Bangkok, 2010.
Thermal diffusivity measurement of porous materials
Abstract:
In this research, the measurement technique for thermal diffusivity of porous
materials using thermography is presented. The major advantage of this technique is
no sensor of temperature measuring device installed on a specimen, so no heat
accumulate in the sensor. Moreover, it is not necessary to have a good sensor
installation skill to make a good contact between the specimen and the sensor of
temperature measuring device. Therefore, the measured temperature distribution
should have more accuracy. The specimen will be installed in an apparatus that has
insulated walls and contains stationary air to reduce heat losses by forced convection
for better results. The specimen is heated using laser beam and the resulting
temperature distribution versus time is recorded by thermographic camera. The
measured data in conjunction with numerical method are used to calculate thermal
diffusivity of the tested specimen. The thermal diffusivities of stainless steel AISI 304
and alumina ceramic having porosity of 0.38 % were measured in this work and the
obtained thermal diffusivities differ from the values in the reference books by 30 %
for stainless steel AISI 304 and by 10 % for alumina ceramic, however, they have the
same order of magnitude.