A new estimation method of thermal diffusivity using analytical inverse solution for one-dimensional heat conduction

Simple measurement of thermal diffusivity and thermal conductivity using inverse solution for one-dimensional heat conduction

Porous and granular materials often defy an accurate description which would identify them. Property values for such media reported in the literature can then serve as guides only and a user of such material who needs accurate property values has to obtain them by measurement on a sample of the specific material with which he is concerned. It is the purpose of the present paper to describe a device by which specific heat, heat conductivity, and thermal diffusivity of particulate materials can be measured rapidly and accurately. The sample has an annular cylindrical shape, and is heated with a uniform heat flux on its inside and outside surfaces. The analysis performed has resulted in closed form expressions for the properties in terms of the measured variables in the quasi-steady state regime. An apparatus was designed and manufactured to verify the analysis. The conductivity of dry sand obtained by this method agrees with that measured in a steady state test within 2.17%.

Measuring thermal properties of particulate materials using constant heating on the inside and outside surfaces of a cylindrical specimen

A New Simultaneous Measuring Method of Thermal Properties by Iterative Calculations

A new method of simultaneous measurement of thermal properties--- thermal conductivity, thermal diffusivity and heat capacity ----- of plane-shaped solids by continuous heating is presented. The principles of the measurement are based on the iterative calculations, that is, the numerically calculated temperature responses of a specimen with assumed thermal properties are compared with the experimental ones, and the above procedure is iterated until the calculated temperature responses coincide with the experimental ones. Necessary conditions of measurement and calculation are determined by theoretical analysis. This method is examined theoretically and experimentally and is shown to be useful for rapid estimation of temperature dependencies of the above thermal properties.

Hiroshi Horiguchi

Papers

A New Simultaneous Measuring Method of Thermal Properties by Iterative Calculations

A New Method of Simultaneous Measurement of Thermal Properties by Iterative Calculations