The KSFM Journal of Fluid Machinery (한국유체기계학회 논문집)

Korean Society for Fluid machinery (한국유체기계학회)
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Tip Gap Flow and Aerodynamic Loss Generation over a Cavity Squealer Tip with the Variation of Pressure-Side Opening Length in a Turbine Cascade

스퀼러팁의 압력면 개방길이 변화에 따른 터빈 익렬 팁간극 유동 특성 및 압력손실

  • 천주홍 (금오공과대학교 기계공학과 대학원) ;
  • 이상우 (금오공과대학교 기계공학과)
  • Received : 2012.01.12
  • Accepted : 2012.11.13
  • Published : 2012.12.01
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Abstract

The effect of pressure-side opening length on three-dimensional flow fields and aerodynamic losses downstream of a cavity squealer tip has been investigated in a turbine rotor cascade for the squealer rim height-to-chord ratio and tip gap height-tochord ratio of $h_{st}/c$ = 5.05% and h/c = 2.0% respectively. The opening length-to-camber ratio is changed to be $OL/c_c$ = 0.0, 0.1, 0.2, 0.3, 0.4, 0.5, and 0.7 The results show that longer OL leads not only to weaker secondary flow but also to lower aerodynamic loss in the tip leakage vortex region, while it significantly widens the area with high aerodynamic loss in the passage vortex region. The aerodynamic loss coefficient mass-averaged all over the measurement plane is kept almost constant for $0.0{\leq}OL/c_c{\leq}0.3$, whereas it increases rapidly for $OL/c_c$ > 0.3 in proportion to $OL/c_c$. There is little deterioration in flow turning with increasing $OL/c_c$.

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References

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