Simultaneous estimations of temperature-dependent thermal conductivity and heat capacity

A hybrid numerical algorithm of the Laplace transform technique and the control-volume method is proposed to simultaneously estimate the temperature-dependent thermal conductivity and heat capacity from temperature measurements inside the material. But, the functional forms of the thermal conductivity and heat capacity are unknown a priori. The whole domain is divided into several sub-layers and then the thermal properties in each sub-layer are assumed to be linear functional forms of temperature before performing the inverse calculation. The accuracy and efficiency of the predicted results can be evidenced from various illustrated cases using simulated exact and inexact temperature measurements obtained within the medium. Results show that good estimations on the thermal properties can be obtained from the knowledge of the transient temperature recordings only at two selected locations. The advantage of the present method is that the relation between the thermal properties and temperature can be determined for various types of boundary conditions even though the early temperature data cannot be obtained. (C) 1998 Elsevier Science Ltd. All rights reserved.