Temperature non-uniformity due to heat conduction and radiation in the pulse calorimetry technique

Abstract

The paper presents an assessment of the unwanted temperature non-uniformity found in high temperature applications of the pulse calorimetry technique. Specimens in the form of a solid cylinder undergoes fast electrical heating and an intense heat radiation at high temperatures, coupled with the heat conduction the specimens? cold ends, make them having a highly non-uniform temperature distribution, both in their radial and axial directions. By using finite element method simulations of a typical pulse calorimetry experiment, the temperature non-uniformity across the specimen diameter and along the specimen effective length has been estimated for different specimen dimensions and materials, as well as for different heating rates. The obtained results suggest that an optimization of experimental parameters, such as the specimen diameter, specimen total and effective length and heating rate, is needed for minimization of the temperature non-uniformity effect.