Ultrasonic Monitoring of Heat Flux through a Solid/Solid Interface

Abstract

Heat flux entering a solid through its heating surface is an important parameter to understand thermal phenomena related to the heat conduction and heat resistance of the heated solid. Ultrasound, due to its high sensitivity to temperature, has the potential to be an effective means for estimating heat flux as well as temperature of heated materials. In this work, an effective ultrasonic method for measuring heat fluxes through an interface between two solid materials is presented. The method is based on the ultrasonic thermometry providing effective determinations of internal temperature distributions, and heat flux can then be estimated from the determined temperature distribution near the heating surface. The feasibility of conducting a real-time monitoring of heat flux by the method is examined through an experiment with a steel plate (30 mm thickness) whose single side is heated by contacting with a hot copper plate. The heat flux and its transient variation during heating and cooling almost agree with those measured using a conventional heat flux sensor inserted into the interface between the steel and copper plates. Thus, it has been demonstrated that the ultrasonic method does work properly to estimate heat fluxes through the solid interface.