Metoda wyznaczania dyfuzyjności cieplnej na podstawie pomiarów termowizyjnych. Podstawy teoretyczne

• Autorzy: Perkowski Z.

Warianty tytułu

EN

A method of determining of thermal diffusivity based on thermographic measurements. Theoretical background

• Języki publikacji: PL

Abstrakty

EN

A theoretical background of new method for thermal diffusivity measurements is presented in the work. It employs thermograms form a IR camera and consist in a determination of thermal diffusivity directly from the classical heat equation in the sourceless case. It utilises an assumption that temperature may be described as the Fourier series in a body during cooling in the homogeneous boundary conditions described by the Newton law and only the first summand in the series is meaningful for sufficiently big Fourier number (Fo>0.3). Thanks to it temperature measurements on the plane surface of investigated body made by a IR camera are sufficient for the method because the second partial derivative of temperature function in the direction perpendicular to the surface of body may be expressed as a linear function of temperature. In such situation all temperature quantities in the heat equation of the points on the external surface of the body may be calculated (with use of proper formulas on the finite differences) at basing on the data recorded by a IR camera during the cooling process. Finally the thermal diffusivity and factors form the introduced linear dependence between temperature and the second partial derivative of temperature in the perpendicular direction to the surface of body may be determined form system of equations obtained from the modified heat equation given at three different points on the surface.

Słowa kluczowe

PL

materiały inżynierskie; dyfuzyjność cieplna; pomiar termowizyjny

EN

engineering materials; thermal diffusivity; thermographic measurement

• Wydawca: Komisja Inżynierii Budowlanej Polskiej Akademii Nauk Oddział w Katowicach
• Czasopismo: Roczniki Inżynierii Budowlanej
• Rocznik: 2010
• Tom: z. 10
• Strony: 71--76
• Opis fizyczny: Bibliogr. 11 poz.

Twórcy

autor

Perkowski Z.

• Politechnika Opolska, Opole

Bibliografia

• [1] Bison P. G., Cernuschi F., Grinzato E., Marinetti S., D. Robba, Ageing evaluation of thermal barrier coatings by thermal diffusivity, Infrared Physics & Technology, 49, 2007, 286-291.
• [2] Dudzik S., A simple method for defect area detection using activate thermography, Opto-electronics Review, 17, 4, 338-344.
• [3] Fodemski T.R. (red.), Pomiary cieplne, Cz. I, Podstawowe pomiary cieplne, Podręczniki akademckie, Mechanika, WNT, Warszawa, 1993, 2001.
• [4] Gi-Won N., Cheol-Won K., Yeong-Moo Y., Akira O., Thermal diffusivity measurement of BMS 10-102 thermal insulation material in a vaccum condition using a cyclic heating method, Thermochimica Acta, 494, 2009, 123-128.
• [5] Kącki E., Równania różniczkowe cząstkowe w zagadnieniach fizyki i techniki, WNT, Warszawa, 1989.
• [6] Laskar J.M., Bagavathiappan M., Sardar M., Jaykumar J. P., Baldev R., Measurement of thermal diffusivity of solids using infrared thermography, Materials Letters, 62, 2008, 2740-2742.
• [7] Martinsons C. D., Levick A. P., Edwards G. J., Measurement of the thermal diffusivity of solids with an improved accuracy, Int. J. Thermophysics, 24, 4, 2003, 1171-1183.
• [8] Mróz Z., Thermographic identification of defects in structures, Proc. CISM – Advanced School on Parameter Identification of Materials and Structures, Udine, 2003.
• [9] Muscio A., Bison P.G., Marinetti S., Grinzato E., Thermal diffusivity measurement in slabs using harmonic and one-dimensional propagation of thermal waves, Int. Journal of Thermal Sciences, 43, 2004, 453-463.
• [10] Piotrowski J. (red.), Czujniki i metody pomiarowe wybranych wielkości fizycznych i składu chemicznego, Pomiary, WNT, Warszawa, 2009.
• [11] Ukrainczyk N., Thermal diffusivity estimation using numerical inverse solution for 1D heat conduction, Int. J. Heat and Mass Transfer, 52, 2009, 5675-5681.