Inverse simulation and experimental verification of temperature-dependent thermophysical properties

Abstract

An inverse method is developed to simultaneously estimate unknown temperature-dependent thermal conductivity and specific heat of a brass rod with knowledge of temperatures taken on the specimen. An experimental process with the brass rod is built for measuring temperatures at some locations to verify the thermal conductivity and specific heat. With known temperature data recorded from the experiment, inverse solutions were rapidly obtained through the Broyden–Fletcher–Goldfarb–Shanno (BFGS) combined simple step method. Results show that the proposed method can estimate thermal properties with low iterations and in a significantly short time compared to other methods. In addition, the estimated temperatures are in very good agreement with the measurement temperature. From experimental verification, the estimated thermal properties are quite close to values obtained by simple tests, with several cases of different heat generation magnitudes. The effect of measurement errors and locations, as well as measured point numbers, on the accuracy of inverse solutions was discussed. According to analysis results, the proposed method, an accurate and efficient method for the prediction of unknown thermal conductivity and specific heat, can be applied to accurately estimate thermophysical properties of various materials.