Application of the hybrid method to transient heat conduction in one-dimensional composite layers

Chen, H.-T.; Lin, Jae Yuh

doi:10.1016/0045-7949(91)90053-o

Cited by 12 publications

(5 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…O problema de transferência de calor em paredes compostas tem sido classicamente modelado utilizando-se a equação da energia, com condições de contorno lineares e em função do tempo (BECKETT;CHU, 1973;CHEN;LIN, 1991;SUN;JIA, 2007;CHANG, 1980 Dentro desse contexto, o presente trabalho busca soluções para melhorar a eficiência energética das edificações, tendo como objetivo: avaliar configurações diversas de paredes compostas por diferentes tipos e disposições de materiais sob a ótica da térmica em edifícios mediante ensaios de laboratório e modelagem matemática.…”

Section: Já Nos Estados Unidos O Buildings Energy Dataunclassified

Análise da transferência de calor em paredes compostas por diferentes materiais

et al. 2010

View full text Add to dashboard Cite

Resumoprojeto de edificações energeticamente eficientes necessita de conhecimentos sobre a transferência de calor proveniente do ambiente externo, a fim de criar soluções que associem diferentes materiais e espessuras às condições desejadas de conforto térmico. O objetivo deste trabalho é avaliar diversos tipos e disposições de materiais em paredes de tijolos maciços, sob a ótica da térmica de edifícios. Para a realização dos experimentos, modelos em escala real foram confeccionados, instrumentados e acoplados a uma câmara térmica, desenvolvida especialmente para esse fim. O problema de transferência de calor foi modelado pela equação da energia, resolvida em Diferenças Finitas Centrais, utilizando-se o Método Implícito. As difusividades térmicas dos materiais foram calculadas resolvendo o Problema Inverso de transferência de calor. Também foi calculado o fluxo de calor e o custo total de cada alternativa, finalizando-se com a obtenção da relação termoeconômica para cada parede. Através da análise termoeconômica pode-se constatar que, apesar de o investimento inicial ser relativamente maior nas paredes mais espessas e/ou com isolamento térmico, estas apresentam um comportamento térmico muito superior às tradicionais. Notadamente, a parede com EPS na face exterior apresentou o melhor desempenho. Palavras

show abstract

Section: Já Nos Estados Unidos O Buildings Energy Dataunclassified

Análise da transferência de calor em paredes compostas por diferentes materiais

et al. 2010

View full text Add to dashboard Cite

show abstract

“…Chen and Lin [6] extended the hybrid application of the Laplace transform technique and the finite element method to transient temperature response of multilayered composites to include nonlinear radiation boundary conditions. In the hybrid method, the time-dependent terms were removed from the problem by the application of the Laplace transform, and then the transformed system was solved using the finite element method.…”

Section: Previous Studiesmentioning

confidence: 99%

“…The absorptivity λ is taken as 0.4 and the ground reflectivity as 0.2. The radiation exchange q r,o is given by: (6) with a surface emissivity ε = 0.9; the sky temperature T sky = T f,o -12°C as recommended in Reference [21]. This part of the outside boundary condition is the reason for the nonlinearity of the problem.…”

Section: Effect Of Insulation Location On Initial Transient Thermal Response Of Wallsmentioning

confidence: 99%

Effect of Insulation Location on Initial Transient Thermal Response of Building Walls

Al-Sanea

Zedan

2001

Journal of Thermal Envelope and Building Science

View full text Add to dashboard Cite

The effect of insulation location on the heat transfer characteristics of building wall elements under initial transient conditions is studied. Thermal performance with an insulation layer placed on the inside of a wall is compared to that when the insulation layer is placed on the outside. The investigation is carried out for the climatic conditions of Riyadh, Saudi Arabia, during representative days for July and January using a finite-volume implicit procedure. The initial temperature distribution across the wall is assumed to be uniform and equal to the daily mean external air temperature. The numerical model is validated against a semi-analytic solution developed for a simple test case. The results of model application under the present conditions show that placing the insulation on the inside gives an instantaneous load that is about 20% of the value for outside insulation during the first few hours in the initial transient process. Besides, the duration of the transient process which leads to steady periodic state, and thus, the period of thermal discomfort due to radiation exchange is much shorter for the inside insulation. The average heat transmission over the first 24 hours of air-conditioning operation with the inside insulation is about one-third of that with the outside insulation. The dynamic R-values are averaged over the first 24 hours and compared for various wall orientations, seasons and insulation locations. It is recommended that for spaces where the air-conditioning system is switched on and off intermittently, the insulation should be placed on the inside.

show abstract

“…To this end, many mathematical models and numerical methods for the analysis of heat transfer in pavements were proposed [5][6][7][8][9]. Besides some empirical methods and formulations to determine maximal and minimal pavement temperature [10][11][12][13][14][15], the main numerical methods used for the analysis of transient heat conduction in layered composites were the Laplace transform [16][17][18], quasi-orthogonal functions [19][20][21], Green function [22,23], the finite-difference method [8,24,25], the finite-element method [26][27][28][29][30][31], hybrid Laplace transform= finite-element method [32][33][34], and the boundary element method [35].…”

Section: Introductionmentioning

confidence: 99%

“…However, its applications will be very difficult if nonlinear boundary conditions and irregular geometry are involved. Chen and Lin [32][33][34] developed a hybrid method, i.e., the Laplace transform mixed with the finite-element method, to resolve one-dimensional transient heat conduction of multilayered slabs, in which the transformed system was solved using the finite-element method. They obtained a good solution under simple boundary conditions without the consideration of solar radiation and ambient temperature variation with time.…”

Section: Introductionmentioning

confidence: 99%

Application of the Laplace Transform and Its Numerical Inversion to Temperature Profile of a Two-Layer Pavement under Site Conditions

Chong¹,

Tramontini²,

Specht³

2009

Numerical Heat Transfer, Part A: Applications

View full text Add to dashboard Cite

The mechanical performance of asphalt pavements is closely related to temperature. On the basis of the Laplace transform, this article presents a method to determine dynamic temperature profiles of pavements under site conditions such as location, air temperature, cloud cover, time of day, day of year, material parameters. The main advantages of the present method are no time steps are needed, and unconditional numerical stability, and rapid convergence. By using the present method, we can separate temperature profile analysis with the followed stress and deformation analysis, which will benefit pavement design.

show abstract

Application of the hybrid method to transient heat conduction in one-dimensional composite layers

Cited by 12 publications

References 21 publications

Análise da transferência de calor em paredes compostas por diferentes materiais

Análise da transferência de calor em paredes compostas por diferentes materiais

Effect of Insulation Location on Initial Transient Thermal Response of Building Walls

Application of the Laplace Transform and Its Numerical Inversion to Temperature Profile of a Two-Layer Pavement under Site Conditions

Contact Info

Product

Resources

About