Use of infrared thermography for the explicit heat flux estimation employing regularized measurements with truncated eigenfunction expansions

Sanches, Emerson L.; Knupp, Diego C.; Stutz, Leonardo Tavares; Abreu, Luiz Alberto da Silva; Neto, Antônio José da Silva

doi:10.1016/j.tsep.2021.101084

Cited by 5 publications

(4 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…A escolha do trucamento da série N T é feito de forma regularizada pelo princípio da discrepância de Morozov's, descrito em Morozov (1996), e aplicado em Hanke (2017), Knupp (2016), Negreiros et al (2020 e Sanches et al (2021).…”

Section: Medidas Transformadas: θExpunclassified

“…O uso da transformac ¸ão integral para obter informac ¸ões sobre as características internas ou causas em processos de transferência de calor vem sendo alvo de diversos estudos, como, por exemplo Naveira- Cotta (2011b), que introduziu o uso de dados de medic ¸ão de temperatura transformada integral para a soluc ¸ão de problemas de transferência de calor inverso objetivando a estimativa simultânea de condutividade térmica espacialmente variável e difusividade térmica na conduc ¸ão de calor unidimensional em meios heterogêneos; Sanches et al (2021) utiliza uma formulac ¸ão explícita com auxílio da transformac ¸ão integral para formular e abordar a validac ¸ão experimental da estimativa explícita de fluxos de calor contorno variáveis no tempo em placas termicamente finas empregando medidas de temperatura obtidas por termografia infravermelha; Knupp (2021) apresenta uma abordagem baseada em um problema de minimizac ¸ão simples, onde é feita a estimativa direta e simultânea da condutividade térmica e capacidade térmica em meios heterogêneos, aplicando diretamente as medidas de temperatura na equac ¸ão de conduc ¸ão de calor transformada; Mascouto et al (2020) coma auxílio da transformac ¸ão integral e diferenc ¸as finitas, em uma formulac ¸ão de domínio único, faz estimativa da condutividade térmica para identificac ¸ão de falhas de contato, considerando um problema de conduc ¸ão de calor dentro de um tubo multicamadas; Abreu et al (2018) faz a detecc ¸ão de falhas de contato, através de um problema inverso de conduc ¸ão térmica, em compósitos laminares, utilizando o método Monte Carlo em cadeia de Markov com medidas transformadas.…”

Section: Introduc ¸ãOunclassified

See 1 more Smart Citation

Esquema Explícito Com Transformações Integrais Para Reconstrução De Termos-Fonte Em Problemas De Condução Do Calor Em Meios Heterogêneos

Oliveira,

Abreu,

Knupp

2024

Anais Do Encontro Nacional De Modelagem Computacional E Encontro De Ciência E Tecnologia Dos Materiais

View full text Add to dashboard Cite

Resumo. Este trabalho aborda a aplicac ¸ão da estimac ¸ão explícita da fonte de calor usando transformadas integrais para problemas de conduc ¸ão de calor em meios heterogêneos, empregando um problema auxiliar de autovalores.As medidas são integralmente transformadas e depois aplicadas à fórmula para a expansão da func ¸ão própria do termo de origem procurado. Os resultados promissores obtidos com esta técnica explícita, com um esforc ¸o computacional mínimo, demonstram sua robustez e aplicabilidade em modelos mais complexos.Palavras-chave: Estimac ¸ão explícita da fonte de calor, Transformadas Integrais, Meios Heterogêneos.

show abstract

Section: Medidas Transformadas: θExpunclassified

Section: Introduc ¸ãOunclassified

Esquema Explícito Com Transformações Integrais Para Reconstrução De Termos-Fonte Em Problemas De Condução Do Calor Em Meios Heterogêneos

Oliveira,

Abreu,

Knupp

2024

Anais Do Encontro Nacional De Modelagem Computacional E Encontro De Ciência E Tecnologia Dos Materiais

View full text Add to dashboard Cite

show abstract

“…Huang and Chaing [8] used a 3D transient model to identify unknown heat source configurations with irregular and moving boundaries. Sanches et al, [9] estimated the time-varying boundary heat flux in a thin plate. The heat generated in the machining process is also an object of research: the turning process by Deppermann and Kneer [10], drilling with lubrication by Tai et al, [11,12] and dry drilling by Huang et al, [13].…”

Section: Introductionmentioning

confidence: 99%

Application of the Conjugate Gradient Method for Predicting Unknown Heat Flux in 2D Plat under Effect of Insulation

Ari Satmoko,

Engkos Achmad Kosasih,

Muhammad Irfan Dzaky

et al. 2023

ARFMTS

View full text Add to dashboard Cite

When an anomaly is discovered during a thermal inspection of industrial equipment, the diagnosis of finding the heat source is made more difficult by the presence of heat insulation. The use of the Conjugate Gradient Method (CGM) to solve the unknown heat flux in Inverse Heat Conduction Problem (IHCP) under insulation condition has been discussed. This method is used to predict a heat flux by utilizing temperature data at any points of measurement. The study deals with the structure of 2D thin plate at steady state. A copper plate with a thickness of 1 mm is used as specimen. White glass wool is used to thermally insulate the plate on the back surface. An electrical heater is plate mounted and operated by varying the DC voltage. A datalogger with thermocouple sensors records plate temperature changes. Software for solving the IHCP based on the CGM was developed. Initially, the software was implemented using synthetic data obtained from the forward heat conduction equations with a known heat flux. Simulated measurement data are assumed to have high accuracy (± 0.1 ºC). Determination of heat flux with the CGM gives very satisfactory results with a low error below 0.12%. The CGM was then applied using experimental data. With a measurement error of ± 0.5 ºC, the computational stopping criterion can still be met satisfactorily. In real installations, equipment is sometimes partially or completely isolated. In the experiment, this phenomenon is simulated by varying the isolation area as follows: 0%, 25%, 50% and 100%. The results of the flux calculation are correlated with the real flux supplied by the electrical heater. Each type of insulation area has a similar curve. By obtaining the correlation equation, the equivalent heat flux from calculation to real and vice versa can be carried out.

show abstract

“…A new explicit approach for identifying boundary source terms was proposed by Knupp and Abreu (2016), using a regularization scheme through the truncation of terms in a series and an associated eigenvalue problem. This proposal was experimentally validated and compared with the MCMC method in Sanches et al (2021), where the same explicit method utilized an explicit formulation with the assistance of an integral transform to address the actual experimental data for estimating time-varying boundary heat fluxes in thin thermally plates using temperature measurements obtained through infrared thermography. Knupp (2021) presented an approach where direct and simultaneous estimation of thermal conductivity and thermal capacity in heterogeneous media is carried out, employing transformed temperatures in the transformed equation.…”

Section: Introductionmentioning

confidence: 99%

Explicit scheme based on integral transforms for estimation of source terms in diffusion problems in heterogeneous media

Oliveira,

Abreu,

Knupp

2023

J. Eng. Exact Sci.

View full text Add to dashboard Cite

The estimation of source terms present in differential equations has various applications, ranging from structural assessment, industrial process monitoring, equipment failure detection, environmental pollution source detection to identification applications in medicine. Significant progress has been made in recent years in methodologies capable of estimating this parameter. This work employs a methodology based on an explicit formulation of the integral transformation to characterize the unknown source term, reconstructing it through the expansion in known eigenfunctions of the Sturm-Liouville eigenvalue problem. To achieve this, a linear model is considered in a heterogeneous medium with known and spatially varying physical properties and two heat sources, with both temporal and spatial dependencies, and only spatial dependence. The eigenvalue problem contains information about the heterogeneous properties and is solved using the generalized integral transformation technique. Additionally, an initial interpolation of the sensor data is proposed for each observation time, making the inverse problem computationally lighter. The solutions of the inverse problem exhibit optimal performance, even with noisy input data and sources with abrupt discontinuities. The temperatures recovered by the direct problem considering the recovered source closely match synthetic experimental data, showing errors less than 1%, ensuring the robustness and reliability of the technique for the proposed application.

show abstract

Use of infrared thermography for the explicit heat flux estimation employing regularized measurements with truncated eigenfunction expansions

Cited by 5 publications

References 29 publications

Esquema Explícito Com Transformações Integrais Para Reconstrução De Termos-Fonte Em Problemas De Condução Do Calor Em Meios Heterogêneos

Esquema Explícito Com Transformações Integrais Para Reconstrução De Termos-Fonte Em Problemas De Condução Do Calor Em Meios Heterogêneos

Application of the Conjugate Gradient Method for Predicting Unknown Heat Flux in 2D Plat under Effect of Insulation

Explicit scheme based on integral transforms for estimation of source terms in diffusion problems in heterogeneous media

Contact Info

Product

Resources

About