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

18 Citations (Scopus)


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
Issue number8
Publication statusPublished - Aug 2007
Externally publishedYes



  • 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

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