A Novel Infrared-Based Experimental Technique to Detect Phase Dynamics on Boiling Surfaces
NURETH-14 - 2011 September 25-30


Presented at:
NURETH-14
2011 September 25-30
Location:
Toronto, Canada
Session Title:
F5-1 Instrumentation Technique

Authors:
Hyungdae Kim (Kyung Hee University)
Jacopo Buongiorno (Massachusetts Institute of Technology)
  

Abstract

Heat transfer in nucleate boiling is strongly affected by the liquid and vapor phase distribution

on the boiling surface. A novel experimental technique for the detection of phases on boiling

surfaces is presented. The technique is based on high-speed infrared (IR) thermometry through

an IR-transparent silicon wafer heater; hence the name DEPIcT, or DEtection of Phase by

Infrared Thermometry. Where the heater surface is wet, the IR camera measures the temperature

of the hot water in contact with the heater. On the other hand, where vapor (whose IR

absorptivity is very low) is in contact with the heater, the IR light comes from the cooler water

beyond the vapor. The resulting IR image appears dark (cold) in dry spots and bright (hot) in

wetted area. Using the contrast between the dark and bright areas, we can visualize the

distribution of the liquid and gas phases in contact with the heater surface, and thus identify also

the liquid-vapor-solid contact line. DEPIcT is able to detect thin liquid layers, through the

analysis of interference patterns. Finally, the technique is applied to nucleate boiling of water at

atmospheric pressure to gain insight into the surface micro-hydrodynamics at high heat fluxes,

all the way up to CHF.

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