图书馆订购 Guest

ISSN Online: 2377-424X

International Heat Transfer Conference 12
August, 18-23, 2002, Grenoble, France

Experimental thermal characterization of semi-transparent media

Get access (open in a dialog) DOI: 10.1615/IHTC12.5310
5 pages

摘要

A new original flash set-up has been developped in order to measure, by an optical way (infrared detector), the transient rear face temperature of semi transparent samples. The flash experiment allows to reach the intrinsic diffusivity through an inverse data treatment using the right combined model. This method is then compared with the gold boundaries method commonly used for the thermal diffusivity measurement of semitransparent materials (where inversion is implemented using the classical conductive model in the case of reflective boundaries and small optical thickness of the sample). Experiments are performed on different materials such as float glass, silica glass and zinc selenide for temperature from 293 K to 700 K. Several radiation boundary conditions are investigated. The sample is either coated with gold (highly reflecting) or is sprayed with a black paint (highly absorbing). By using highly reflecting boundaries and a layer with a small optical thickness, internal radiative effects are small whereas the case of black boundaries emphasizes the radiative effects. This experimental work allowed to measure the intrinsic diffusivity of semi-transparent media in a precise way (the error does not exceed 5 %). This study is a contribution in the thermal characterization of semi-transparent media since it allows to reach the phononic diffusivity of participating media.