The KSFM Journal of Fluid Machinery (한국유체기계학회 논문집)

Korean Society for Fluid machinery (한국유체기계학회)
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Effect of Tip Gap Height on Heat/Mass Transfer over a Cavity Squealer Tip

팁간극높이가 전면스퀼러팁 표면의 열전달 특성에 미치는 영향

  • Kang, Dong Bum (Graduate School, Kumoh National Institute of technology) ;
  • Moon, Hyun Suk (Graduate School, Kumoh National Institute of technology) ;
  • Lee, Sang Woo (Department of Mechanical Engineering, Kumoh National Institute of technology)
  • 강동범 (금오공과대학교 대학원) ;
  • 문현석 (금오공과대학교 대학원) ;
  • 이상우 (금오공과대학교 기계공학과)
  • Received : 2013.03.09
  • Accepted : 2013.10.16
  • Published : 2013.12.01
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Abstract

The effect of tip gap height on heat/mass transfer characteristics on the floor of cavity squealer tip has been investigated in a turbine cascade for power generation by employing the naphthalene sublimation technique. The squealer rim height is chosen to be an optimal one of $h_{st}/c$ = 5.51% for the tip gap height-to-chord ratios of h/c = 1.0, 2.0, 3.0 and 4.0%. The results show that heat transfer on the cavity floor is strongly dependent upon the behavior of the cavity flow falling down onto the floor. For lower h/c, the floor heat transfer is influenced by the tip leakage flow falling down along the inner face of the suction-side squealer, whereas the floor heat transfer for higher h/c is augmented mainly due to the impingement of leakage flow on the floor near the leading edge. Compared to the plane tip surface heat transfer, the cavity floor heat transfer is less influenced by h/c. For h/c = 1.0%, the average thermal load is as low as a half of the plane tip surface one, and the difference in the thermal load between the two cases tends to decrease with increasing h/c.

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References

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