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Type: Artigo
Title: Inverse analysis with integral transformed temperature fields: Identification of thermophysical properties in heterogeneous media
Author(s)/Inventor(s): Naveira-Cotta, Carolina Palma
Cotta, Renato Machado
Orlande, Helcio Rangel Barreto
Abstract: Indisponível.
Abstract: The objective of this work is to introduce the use of integral transformed temperature measured data for the solution of inverse heat transfer problems, instead of the common local transient temperature measurements. The proposed approach is capable of significantly compressing the measured data through the integral transformation, without losing the information contained in the measurements and required for the solution of the inverse problem. The data compression is of special interest for modern measurement techniques, such as the infrared thermography, that allows for fine spatial resolutions and large frequencies, possibly resulting on a very large amount of measured data. In order to critically address the use of integral transformed measurements, we examine in this paper the simultaneous estimation of spatially variable thermal conductivity and thermal diffusivity in one-dimensional heat conduction within heterogeneous media. The direct problem solution is analytically obtained via integral transforms and the related eigenvalue problem is solved by the Generalized Integral Transform Technique (GITT). The inverse problem is handled with Bayesian inference by employing a Markov Chain Monte Carlo (MCMC) method. The unknown functions appearing in the formulation are expanded in terms of eigenfunctions as well, so that the unknown parameters become the corresponding series coefficients. Such projection of the functions in an infinite dimensional space onto a parametric space of finite dimension also permits that several quantities appearing in the solution of the direct problem be analytically computed. Simulated measurements are used in the inverse analysis; they are assumed to be additive, uncorrelated, normally distributed, with zero means and known covariances. Both Gaussian and non-informative uniform distributions are used as priors for demonstrating the robustness of the estimation procedure.
Keywords: Integral transforms
Heterogeneous media
Heat conduction
Inverse problem
Thermophysical properties
Bayesian inference
Production unit: Núcleo Interdisciplinar de Dinâmica dos Fluidos
Publisher: Elsevier
In: International Journal of Heat and Mass Transfer
Volume: 54
Issue: 7-8
Issue Date: 7-Jan-2011
DOI: 10.1016/j.ijheatmasstransfer.2010.11.042
Publisher country: Brasil
Language: eng
Right access: Acesso Aberto
ISSN: 0017-9310
Appears in Collections:Engenharias

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