| Journal: | Revista mexicana de física |
| Database: | PERIÓDICA |
| System number: | 000429664 |
| ISSN: | 0035-001X |
| Authors: | Hernández Wong, J1 Rojas Trigos, J.B1 Nogal, U1 Suárez, V2 Marín, E1 Calderón, A1 |
| Institutions: | 1Instituto Politécnico Nacional, Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada, Ciudad de México. México 2Universidad Autónoma Metropolitana, Departamento de Química, Iztapalapa, Ciudad de México. México |
| Year: | 2019 |
| Season: | Ene-Feb |
| Volumen: | 65 |
| Number: | 1 |
| Country: | México |
| Language: | Inglés |
| Document type: | Artículo |
| Approach: | Analítico, teórico |
| English abstract | To induce temperature changes on the sample surface by the incidence of a monochromatic modulated light beam and detect the changes produced in the thermal radiation emission, is the basic principle of the infrared photothermal radiometry technique. Until now, in order to analyze the thermal response mathematical models based in an one-dimensional model were used considering a sample with a finite thickness and an infinite incidence surface, as well as the linear approximation of the Stefan-Boltzmann Law in the calculus of the heat losses due to thermal radiation. In this work, analytical and numerical models for the 2D heat diffusion in homogenous finite solid samples, are presented. These models were obtained by solving the heat diffusion equation, under cylindrical symmetry, considering mixed boundary conditions to include radiation and convection heat losses through the surfaces of the sample, and a monochromatic Gaussian excitation beam impinging on the front of the sample. The analytical models were obtained by solving the governing equations, considering the well-known linear approximation of the Stefan-Boltzmann law in the calculus of the heat losses due to thermal radiation. To analyse the effects of the nonlinearity of the heat losses by thermal radiation on the thermal transient response, in the numerical model it was taken into account the full expression of the Stefan-Boltzmann law, and the transport equation was solved numerically by means of the Finite Element Method (FEM). The analytical solution for the oscillatory thermal response reveals the close dependence of the thermal response on the ratio of thickness to the radius of the sample, represented by the form factor sf. Both, the analytical and the numerical solutions were employed to simulate the thermal response of homogenous materials, and compared with experimental results reported elsewhere by part of our same research group. Finally, the difference between the thermal response pre |
| Disciplines: | Física y astronomía |
| Keyword: | Electromagnetismo, Transferencia de calor, Radiometría fototérmica infrarroja, Propiedades térmicas, Condiciones límite de Robin, Método de elementos finitos |
| Keyword: | Electromagnetism, Heat transfer, Infrared photothermal radiometry, Thermal properties, Robin boundary conditions, Finite element method |
| Full text: | Texto completo (Ver HTML) Texto completo (Ver PDF) |
