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The Solution of the Inverse Problem of Identifying the Thermal Conductivity Tensor in Anisotropic Materials

Authors :
Yurii M. Matsevytyi
Valerii V. Hanchyn
Source :
Journal of Mechanical Engineering, Vol 24, Iss 3, Pp 6-13 (2021)
Publication Year :
2021
Publisher :
NAS of Ukraine, A. Pidhornyi Institute of Mechanical Engineering Problems, 2021.

Abstract

On the basis of A. N. Tikhonov's regularization theory, a technique has been developed for solving inverse heat conduction problems of identifying the thermal conductivity tensor in a two-dimensional domain. Such problems are replaced by problems of identifying the principal heat conductivity coefficients and the orientation angle of the principal axes, with the principal coefficients being approximated by Schoenberg’s cubic splines. As a result, the problem is reduced to determining the unknown coefficients in these approximations and the orientation angle of the principal axes. With known boundary and initial conditions, the temperature in the domain will depend only on these coefficients and the orientation angle. If one expresses it by the Taylor formula for two terms of series and substitutes it into the Tikhonov functional, then the determination of the increments of the coefficients and the increment of the orientation angle can be reduced to solving a system of linear equations with respect to these increments. By choosing a certain regularization parameter as well as some functions for the principal thermal conductivity coefficients and the orientation angle as an initial approximation, one can implement an iterative process for determining these coefficients. After obtaining the vectors of the coefficients and the angle of orientation as a result of the converging iterative process, it is possible to determine the root-mean-square discrepancy between the temperature obtained and the temperature measured as a result of the experiment. It remains to choose the regularization parameter in such a way that this discrepancy is within the root-mean-square discrepancy of the measurement error. When checking the efficiency of using the proposed method, a number of two-dimensional test problems for bodies with known thermal conductivity tensors were solved. The influence of random measurement errors on the error in the identification of the thermal conductivity tensor was analyzed.

Details

Language :
English, Russian, Ukrainian
ISSN :
27092984 and 27092992
Volume :
24
Issue :
3
Database :
Directory of Open Access Journals
Journal :
Journal of Mechanical Engineering
Publication Type :
Academic Journal
Accession number :
edsdoj.6ce20830cd46472a89572f1bf4290b00
Document Type :
article
Full Text :
https://doi.org/10.15407/pmach2021.03.006