Use of Synchronized , Infrared Thermometry and High - Speed Video for Generation of Space - and Time - Resolved High - Quality Data on Boiling Heat Transfer

Boiling heat transfer is a key thermal limit in nuclear systems. However, for decades, its modeling has relied on speculative hypotheses and a good dose of empiricism. As researchers now start to develop more mechanistic models, the need for high-quality high-resolution data on the bubble nucleation and growth cycle is increasing. Specifically, nucleation site density, bubble departure diameter and frequency data, are necessary input for and validation of the source terms in interfacial area transport models, CFD ‘multi-fluid’ models, as well as direct numerical simulation models of boiling based on interface tracking methods. In this paper we present an approach based on synchronized infrared thermometry and highspeed video ‘through’ the heater that enables simultaneous measurement of the nucleation site density, bubble growth rate (including bubble departure diameter), bubble departure frequency (including wait time), time-resolved 2D temperature distribution and phase distribution on the boiling surface, all in a relatively effortless manner.