Department of Mechanical Engineering, Nagaoka University of Technology, Japan

 

Keywords: Ultrasonic thermometry, Internal temperature, Temperature distribution, Heated materials, Frictional surface, Heat flux, Laser ultrasound, Condition monitoring

 

Abstract

This talk presents recent advances in ultrasonic thermometry aimed at accurately monitoring internal temperature distributions in heated materials. The ultrasonic method offers the unique advantage of measuring internal temperature distributions with relatively high spatial and temporal resolution in materials being heated where conventional approaches such as thermocouples and infrared techniques are difficult to apply.

The ultrasonic thermometry we developed is essentially a hybrid approach that combines the ultrasonic pulse-echo method with finite-difference analysis for one-dimensional unsteady heat conduction. Its feasibility was validated through experiments on a thick steel plate subjected to one-sided heating. The reconstructed temperature profiles showed good agreement with reference thermocouple data, confirming the method’s accuracy and robustness. 

Several application studies are also introduced, including temperature monitoring near a frictional surface, in-situ measurement of heat flux entering from the interface between dissimilar materials, and non-contact temperature profiling of a rotating heated steel cylinder using a laser-ultrasound technique. This presentation will also discuss not only the fundamental principles of the ultrasonic thermometry but also its potential as a versatile tool for high-temperature monitoring and process diagnostics in manufacturing and materials engineering.