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Thermal diffusivity of nonflat plates using the flash method
Agustín Salazar1, Raquel Fuente, Estibaliz Apiñaniz
1Departamento de Física Aplicada, Escuela Técnica Superior de Ingeniería, Universidad del País Vasco, Bilbao, Spain. agustin.salazar@ehu.es
The Review of Scientific Instruments
|February 2, 2011
Summary
The flash method now measures thermal diffusivity in curved samples like cylinders and spheres. This extends the standard technique beyond flat materials, establishing a curvature limit for accurate thermal property assessment.
Area of Science:
- Materials Science
- Thermal Analysis
- Solid-State Physics
Background:
- The flash method is a standard technique for measuring thermal diffusivity in solid samples.
- Traditionally, this method is limited to flat, opaque samples.
- Accurate thermal property measurement is crucial for material selection and performance prediction.
Purpose of the Study:
- To extend the applicability of the flash method to non-flat solid samples.
- To investigate the thermal diffusivity measurement of cylindrical and spherical samples.
- To establish theoretical limits for applying the standard flash method formula to curved geometries.
Main Methods:
- Development of a theoretical model for heat transfer in non-flat samples subjected to a thermal pulse.
- Adaptation of the standard flash method for analyzing temperature evolution on the rear surface of curved samples.
- Experimental validation using lead foils with cylindrical shapes.
Main Results:
- The theoretical model demonstrates that the standard flash method formula is applicable to cylindrical and spherical samples within certain curvature limits.
- A specific curvature limit was established, beyond which the simplified formula may not be accurate.
- Experimental results on cylindrical lead foils validated the extended theoretical model.
Conclusions:
- The flash method can be successfully extended to measure the thermal diffusivity of non-flat samples, including cylindrical and spherical geometries.
- The study provides a theoretical framework and experimental evidence for this extension.
- This advancement broadens the scope of the flash method for thermal property characterization of diverse sample shapes.
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