Estimation of energy absorption rate and temperature distributions in short-pulse laser heating of metals with a dual-phase-lag model

In this study, an inverse algorithm based on the conjugate gradient method and the discrepancy principle is applied to solve the inverse hyperbolic heat conduction problem with a dual-phase-lag model to estimate the unknown space- and time-dependent energy absorption rate in a thin metal film exposed to short-pulse laser heating from the temperature measurements taken within the medium. Subsequently, the temperature distributions in the metal film can be determined as well. The inverse solutions are justified based on the numerical experiments in which two different energy absorption rates are estimated. The temperature data obtained from the direct problem are used to simulate the temperature measurements. The influence of measurement errors upon the precision of the estimated results is also investigated. Results show that an excellent estimation on the laser energy absorption rate can be obtained for the test cases considered in this study.