Journal of the Korean Society of Propulsion Engineers (한국추진공학회지)

The Korean Society of Propulsion Engineers (한국추진공학회)
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Effect of Groove Shape of Blade Tip on Tip Surface Heat Transfer Coefficient Distributions of a Turbine Cascade

블레이드 팁의 Groove 형상이 터빈 캐스케이드 팁 열전달 계수분포에 미치는 영향에 대한 실험적 연구

  • 노영철 (한국항공대학교 항공우주 및 기계공학과) ;
  • 조용화 (한국항공대학교 항공우주 및 기계공학과) ;
  • 이용진 (한국항공대학교 항공우주 및 기계공학과(국방기술품질원)) ;
  • 김학봉 (한국항공대학교 항공우주 및 기계공학과) ;
  • 곽재수 (한국항공대학교 항공우주 및 기계공학과)
  • Received : 2010.05.31
  • Accepted : 2010.11.04
  • Published : 2010.12.30
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Abstract

In this study, the conventional plane tip, double squealer tip, and various groove tip blades were tested in a linear cascade in order to measure the effect of the tip shapes on tip surface heat transfer coefficient distributions. Detailed heat transfer coefficient distributions were measured using a hue-detection based transient liquid crystals technique. Two tip gap clearances of 1.5% and 2.3% of blade span were investigated and the Reynolds number based on cascade exit velocity and chord length was $2.48{\times}10^5$. Results showed that the overall heat transfer coefficients on the tip surface with various grooved tips were lower than those with plane tip blade. The overall heat transfer coefficient on grooved along suction side tip was lower than that on the squealer tip.

본 연구에서는 팁 형상이 가스터빈 블레이드의 팁 열전달에 미치는 영향을 알아보기 위하여 선형 캐스케이드의 블레이드에 설치된 평면 팁, 스퀼러 팁, Groove 팁들에 대하여 열전달 계수가 측정되었다. 블레이드 팁에서의 열전달 계수는 색상검출방식에 기반을 둔 천이액정법을 이용하여 측정되었으며 각각의 팁 형상에 대하여 팁 간극은 블레이드 스팬의 1.5%와 2.3% 두 조건에서 실험을 수행하였다. 캐스케이드 출구 속도와 블레이드 코드길이에 기초를 둔 Reynolds 수는 $2.48{\times}10^5$ 이다. Groove 팁 표면에서의 열전달 계수는 평면 팁보다 낮게 측정되었으며, 특히 흡입면을 따라 경사진 홈이 파인 팁에서는 스퀼러 팁보다 낮은 열전달 계수가 측정되었다.

Keywords

References

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