Dependence of Entropy Production Density on the Rate of Temperature Change in Linear Thermodynamics

Abstract

Experimental thermograms obtained on samples of different shapes and sizes under spontaneous cooling, pulsed resistive heating, or laser surface heating of the solid phase of high-temperature metals are analyzed. It is shown that all the thermograms can be ascribed to a linear thermodynamic regime. A linear dependence of the entropy production density on the rate of variation of the temperature is found on analyzing the thermograms. This means that the rate of variation in the temperature can be regarded as an additional variable for the entropy production density in the linear regime and can be used for representing properties measured in a nonstationary thermal regime.