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Author
Miller, M. S. | Kotlar, A. J.
Title
New Technique for the Simultaneous Measurement of Thermal Diffusivity and Thermal Conductivity of Small Energetic-Material Specimens.
Coporate
Army Research Laboratory, Aberdeen Proving Ground, MD
Report
ARL-TR-1321
March 1997
31 p.
Keywords
thermal diffusivity | thermal conductivity | propellants | heat flux | data analysis
Abstract
An experimental technique to simultaneously measure the thermal diffusivity and thermal conductivity of small specimens of thermal-insulator materials is described. Experimental conditions that approach the mathematical idealization of a one-dimensional, infinite, two-component, composite solid whose planar interface is subjected to a step-function heat flux are developed. The heat flux is generated by resistive heating of a thin metallic foil. Although this principle has been exploited previously, the present technique permits specimens with volumes two orders of magnitude smaller than prior work based on the same idealization. A number of difficulties related to small specimen volume are identified and overcome. Another improvement over past efforts is the use of nonlinear least-squares analysis to determine the optimum values for diffusivity and conductivity. A comparison of measurements of these properties for acrylic and Pyrex glass with literature values suggests that the technique affords accuracies of about 5% for materials in this range.