Use of a pseudo-random heating excitation to investigate the thermal properties of thermally fragile materials
Fethi Albouchi, Mourad Fetoui, Fabrice Rigollet, Foued Mzali and Sassi Ben Nasrallah
In this numerical study, a photothermal method with random excitation is implemented in order to measure the thermal diffusivity of thermally fragile materials. The principle of this technique is based on rebuilding the sample impulse response through input-output cross-correlation. A Doptimality criterion is used to determine the optimal duration of the experiment. The thermophysical properties are identified through the rebuilt impulse response using an iterative method which minimizes the gap between simulated measurements and theoretical temperature calculated using the thermal quadripoles method. The obtained results show a good agreement with literature values.
Keywords: Photothermal method, pseudo-random excitation, optimal design, parameter estimation, thermal diffusivity.