An alternative sensitivity method for a two-dimensional inverse heat conduction-radiation problem based on transient hot-wire measurements

摘要

An inverse approach based on hot-wire measurements has been proposed to simultaneously estimate radiative and conductive properties of metallic/ ceramic foam samples, from a unique experiment. A theoretical model of two-dimensional transient conduction-radiation heat transfer in a cylindrical medium allowed to accurately simulate real temperature measurements in a hot-wire cell. Based on this model, the Levenberg-Marquardt method (LMM) has been adopted as the inverse technique. According to a sensitivity and correlation analysis, measuring points were suitably chosen and a proposed two-stage estimation technique was successfully performed. Due to the dimension of the model and to the number of identified parameters, a large computational time was required to calculate the sensitivity matrix. The Broyden's combined update method has been adopted as an alternative sensitivity method, whose combination with the LMM reduced considerably the amount of computation. This reduction reached 69% for each of the studied samples.