Theoretical analysis of applying thermography and inverse solutions to determine thermal properties of cementitious materials

Abstract

This work discusses results of the theoretical analysis performed in order to study technical feasibility of an experiment and measurement set-up for determining thermal properties of cementitious materials. The cylindrical test-piece under the study is modelled to compose two subdomains. The medium in the first subdomain, the properties of which are required, is heated by the surface heat source at its free extremity while being in contact with the second medium with predetermined properties, known as reference material. There is a special provision in the analysis that all the required measurements could be simulated by adding random errors to numerical results from the direct solutions.All algorithms to determine the key parameters are based on the sensitivity analysis. The analysis is designed to process a large number of surface temperature measurements normally collected using a thermographic camera. These are processed through the inverse analysis in order to determine the thermal properties of the measured (cementitious) material as well as auxiliary thermal quantities/parameters occurring within the considered set-up.Outcomes of extensive computations show dependence of the values of identified thermal properties on the accuracy of the temperature measurements as well as on some auxiliary thermal quantities.

Modeling and Measuring Thermodynamic and Transport Thermophysical Properties: A Review

“…Wawrzynek et al [88] discussed the results of a theoretical analysis to study the technical feasibility of an experimental setup for determining the thermal properties of materials. In this work, all the required measurements were simulated by adding random errors to numerical results of the direct solutions.…”

“…Many surface temperature measurements were collected through an IR camera. Through an inverse analysis the thermal properties of the measured material were determined, as well as auxiliary thermal quantities characterizing the setup [88].…”