Thermal measurements using ultrasonic acoustical pyrometry

Area of Science:

• Materials Science
• Thermodynamics
• Non-destructive Testing

Background:

• Classical temperature measurement is often impractical in harsh environments or with limited physical access.
• Ultrasonic reflections offer a non-contact method for thermal analysis.
• Ill-posed heat transfer problems require advanced inversion techniques for accurate solutions.

Purpose of the Study:

• To present two ultrasonic-based methods for determining interface and surface temperatures.
• To compare the accuracy of these methods against verification examples and field data.
• To validate the findings against established empirical relationships in engineering applications.

Main Methods:

• Utilizing ultrasonic energy reflections from geometric discontinuities to infer interface temperatures.
• Applying inversion methods, common in ill-posed heat transfer problems, to ultrasonic data for enhanced surface temperature and heat flux measurement.
• Conducting verification tests and field data collection to assess method performance.

Main Results:

• Both presented ultrasonic methods successfully predicted interface temperatures under challenging conditions.
• The inversion-based ultrasonic approach significantly improved the accuracy of surface temperature and heat flux measurements.
• Results from both methods showed good agreement with an empirical relationship used in large caliber gun design.

Conclusions:

• Ultrasonic thermometry provides a viable alternative to classical methods in inaccessible or harsh environments.
• Advanced inversion techniques enhance the precision of ultrasonic thermal measurements.
• The validated ultrasonic methods have practical applications in fields requiring accurate thermal analysis, such as in the design of large caliber guns.