A method for predicting thermal waves in dual-phase-lag heat conduction

We predict whether thermal waves exist or not in dual-phase-lag heat conduction by measuring the time lag ratio (τ_q/τ_T. In this method, a one-dimensional model of cylindrical heating is developed and solved by the method of Laplace transform. The time lag ratio is then derived from the time derivative of the square of excess temperature on the heater wall in the initial heating stage. Experimentally, we also applied this method to measure the time lag ratios for sand and lean pork, both of which are less than 1 within acceptable measurement uncertainty, indicating no thermal waves generated. This method is of great importance for the application of dual-phase-lag heat conduction model since it can predict existence of thermal waves through a simple experiment.