Non-intrusive heat flux measurements using ultrasound

Papers presented to the 11th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 20-23 July 2015.Heat flux values are needed in the field of fluid mechanics and heat transfer to quantify the transfer of heat within systems. Maximizing or minimizing the thermal energy transfer in many systems is crucial to their optimization. In this study, we demonstrate how heat flux measurements can be made using ultrasound. Tests have been conducted on a series of metals heated at one end using a calibrated infrared source. Using ultrasonic sensors located remotely from the heated surface the time-of-flight variations of heated surface echoes are used to calculate heat flux. The temporal variation of heat flux determined using ultrasonic data is identical to that derived from transient thermal models. In this study the value of ultrasonicbased heat flux estimates were found to be in good agreement with independent estimates computed from thermal transport models.am201