Thermal Diffusivity of Heterogeneous Materials
- 1 January 1971
- journal article
- research article
- Published by AIP Publishing in Journal of Applied Physics
- Vol. 42 (1) , 267-271
- https://doi.org/10.1063/1.1659581
Abstract
The concept of the thermal diffusivity as a characteristic constant of a heterogeneous material is examined. By considering the derivation of the heat conduction equation, and the concept of the thermal wavelength associated with a particular problem, a general criterion for the homogeneity of a material under transient conditions is obtained. This criterion limits the scale of heterogeneity of the material (expressed as a lattice spacing) to be much smaller than the minimum thermal wavelength associated with the problem. The flash method of measuring the thermal diffusivity is considered in detail. The criterion developed limits the particle size of a particulate phase to be much smaller than the sample thickness for the sample to be considered homogeneous, and for the usual relation between the thermal diffusivity and thermal conductivity to hold.This publication has 4 references indexed in Scilit:
- Thermal Conductivity and Heat Capacity of the Monophosphide and Monosulfide of PlutoniumJournal of the American Ceramic Society, 1968
- Thermal Conductivity and Heat Capacity of the Monocarbide, Monophosphide, and Monosulfide of UraniumJournal of Applied Physics, 1967
- Finite Speed of Propagation in Heat Conduction, Diffusion, and Viscous Shear MotionAmerican Journal of Physics, 1967
- Flash Method of Determining Thermal Diffusivity, Heat Capacity, and Thermal ConductivityJournal of Applied Physics, 1961