A flow boiling heat transfer investigation of FC-72 in a microtube using liquid crystal thermography

R. Muwanga, Ibrahim Hassan

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

This paper presents experimental measurements of boiling heat transfer in a 1.067 mm inner diameter tube, using liquid crystal thermography for wall temperature measurement. The study was motivated by the two-phase microchannel pumped cooling loop, a recent technology proposed for thermal management of tomorrow's high-end electronics. The working fluid was FC-72, which is a dielectric coolant and measurements were obtained in a closed loop test facility. A unique flow boiling onset was observed whereby a large wall temperature gradient travels along the tube. During flow boiling conditions, wall temperature fluctuations have been observed. The use of a thermographic technique has added insight into the flow boiling characteristics and acts as a partial flow visualization method. Local heat transfer coefficients are presented and compared with correlations for both macro- and microchannels. The heat transfer coefficient is found to be influenced by the heat flux at a lower mass flux but only mildly at a higher mass flux.

Original languageEnglish
Pages (from-to)977-987
Number of pages11
JournalJournal of Heat Transfer
Volume129
Issue number8
DOIs
Publication statusPublished - Aug 2007
Externally publishedYes

Fingerprint

boiling
Boiling liquids
wall temperature
heat transfer
liquid crystals
Heat transfer
microchannels
Microchannels
heat transfer coefficients
Heat transfer coefficients
Mass transfer
tubes
working fluids
flow visualization
coolants
test facilities
Flow visualization
Test facilities
Temperature measurement
Coolants

Keywords

  • Boiling
  • Dielectric fluid
  • Heat transfer
  • Microchannel
  • Microtube
  • Thermochromic liquid crystal

ASJC Scopus subject areas

  • Mechanical Engineering
  • Physical and Theoretical Chemistry
  • Fluid Flow and Transfer Processes

Cite this

A flow boiling heat transfer investigation of FC-72 in a microtube using liquid crystal thermography. / Muwanga, R.; Hassan, Ibrahim.

In: Journal of Heat Transfer, Vol. 129, No. 8, 08.2007, p. 977-987.

Research output: Contribution to journalArticle

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