Termografia por infravermelho aplicada à análise teórico-experimental da estimativa de fluxo de calor bidimensional transiente via modelos hierárquicos e métodos de Monte Carlo com cadeias de Markov

• Autor(a) principal: Neves, Gabriel Teixeira Soares das
• Data de Publicação: 2019
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/13628
• topic: Heat flux estimate; Bayesian inference; Infrared thermography; Markov random fields; Estimativa de fluxo de calor; Inferência Bayesiana; Termografia por infravermelho; Campos aleatórios de Markov; Calor - Transmissão Medição; Calor - Radiação e absorção; Calorimetria; Termografia; Estatistica matemática; Tecnologia infravermelha; Markov, Processos de; CNPQ::CIENCIAS EXATAS E DA TERRA::CIENCIA DA COMPUTACAO

In this work the problem of heat flux estimation with two-dimensional and temporal variations applied to one of the surfaces of a thermally thin metal plate is addressed. Infrared thermography images provide experimental data used to verify the direct problem and formulation of the inverse problem. The direct problem, that in this work consists in the identification of the temperature field on a thermally thin plate, was solved by using the finite difference method. The solution of the inverse problem is obtained using a Bayesian approach, using the Markov chains Monte Carlo Method. For the regularization of the inverse problem it is proposed the application of Markov Random Fields priors information. When possible, the regularization parameter of the a priori information was estimated as part of the problem of Bayesian inference, through the use of a hyperpriori in a hierarchical model to estimate the desired quantities. The results, using simulated and real measurements, show that the method is able to accurately estimate the heat flux in the different cases studied, including a case elaborated in the laboratory, expanding results and contributing originally to literature, with the estimation of heat fluxes that present complex behaviors and regularization of large inverse problems via the use of adequate a priori information.