Abstract

LIMA E SILVA, S. M. M.  and  LIMA E SILVA, A. L. F.. Estimation of thermal effusivity of polymers using the thermal impedance method. Lat. Am. appl. res. [online]. 2010, vol.40, n.1, pp.67-73. ISSN 0327-0793.

Thermal impedance is a way of defining the characteristics of thermal systems. It is a function that represents the relation between the frequency components of temperature and heat flux. From the experimental point of view, it is determined simply by measuring the heat flux and the temperature, simultaneously. In this work, these signals are measured only on the frontal surface of the sample. The experimental technique proposed here can be well adapted for making in situ measurements. A one-dimensional semi-infinite thermal model is used. For the semi-infinite model, just the thermal effusivity, b, can be estimated. The thermal effusivity is estimated for three polymers. An objective function representing the difference between experimental and theoretical values of the modulus of the thermal impedance function is minimized. For all cases studied in this work the thermal effusivity is in good agreement with literature. In addition an uncertainty analysis is also presented.

Keywords : Thermal Properties Estimation; Heat Conduction; Optimization; Experimental Methods; Thermal Impedance.

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