Calibrating for viewing angle effect during heat transfer measurements on a curved surface

Tat Leung Chan, S. Ashforth-Frost, K. Jambunathan

Research output: Journal article publicationJournal articleAcademic researchpeer-review

79 Citations (Scopus)

Abstract

Liquid crystal thermography (LCT) has been widely used for the determination of surface heat transfer distribution. However, this technique is sensitive to illumination and viewing angle and therefore limited to surfaces with only slight curvature. A liquid crystal calibration technique using true-colour image processing system has now been developed to alleviate the effect of viewing angle on oblique/curved surfaces. Application of the calibration and transient liquid crystal thermographic techniques and uncertainty analysis to a heated air slot jet impinging on a semi-cylindrical convex surface has been demonstrated. It is shown that the local heat transfer coefficient may be overestimated by up to 39.1% at a viewing angle of 69° from the normal under test conditions. However, the overall uncertainty in heat transfer coefficient can be significantly reduced from the maximum value of 36.3% to within 11.1% by using the implemented viewing calibration technique.
Original languageEnglish
Pages (from-to)2209-2223
Number of pages15
JournalInternational Journal of Heat and Mass Transfer
Volume44
Issue number12
DOIs
Publication statusPublished - 8 May 2001

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Mechanical Engineering
  • Fluid Flow and Transfer Processes

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