터빈 블레이드 끝단 형상 변화에 따른 블레이드 표면 및 슈라우드에서의 열전달 특성 변화

다국어 초록 (Multilingual Abstract)

The effect of blade tip geometry has been investigated on blade near-tip surface and shroud heat transfer. The local mass transfer coefficients were measured on the blade surface and shroud using a naphthalene sublimation technique. A low speed stationary annular cascade with a single turbine stage was used. The chord length of the tested blade is 150 ㎜ and the mean tip clearance of the blade having flat tip is 2.5% of the blade chord. To investigate the effect of tip geometry, the blade with squealer rim was used and the results were compared with the flat tip cases. The average cavity depth to chord ratio (H/C) is 2.2% and the rim width is 5 ㎜ (w/C=3.3%). The inlet flow Reynolds number based on chord length and incoming flow velocity is fixed to 1.5×10?. The results show that the squealer rim reduces the amount of tip leakage flow, which results in the increased effect on the blade surface. The reason is that the momentum of tip leakage flow is reduced and then the tip leakage vortex is closer to the surface than the flat tip case. On shroud, the average value is almost the same as that for the flat-tip blade although the local distribution is quite different.

목차 (Table of Contents)

• Abstract
• 1. 서론
• 2. 실험 장치 및 방법
• 3. 열/물질전달계수
• 4. 실험결과 및 토의
• 5. 결론
• 참고문헌