DOI QR코드

DOI QR Code

Heat/Mass Transfer Characteristics on Shroud with Turbine Blade Tip Clearances

터빈 블레이드 말단과 슈라우드 사이의 간극변화에 따른 슈라우드에서의 열/물질전달 특성

  • Published : 2001.03.01

Abstract

The present study is conducted to investigate the local heat/mass transfer characteristics on the shroud with blade tip clearances. The relative motion between blade and shroud has little influence on the overall heat transfer characteristics, except some local effects. Therefore, the relative motion between the blade and shroud is neglected in this study. A naphthalene sublimation method is employed to determine the detailed local heat/mass transfer coefficients on the surface of the shroud. The tip clearance is changed from 0.66% to 2.85% of the blade chord length. The flow enters the gap between the blade tip and shroud at the pressure side due to the pressure difference. Therefore, the heat/mass transfer characteristics on the shroud are changed significantly from those with endwall. At first, high heat/mass transfer occurs along the profile of blade at the pressure side due to the entrance effect and acceleration of the gap flow. Then, the heat/mass transfer coefficients on the shroud increase along the suction side of the blade because tip leakage vortices are generated and interact with the main flow. The results show that the heat/mass transfer characteristics are changed largely with the gap distance between the tip of turbine blade and the shroud.

Keywords

References

  1. Metzger, D. E., Dunn, M. G. and Hah, C., 1991, 'Turbine Tip and Shroud Heat Transfer,' Trans. ASME, Journal of Turbomachinery, Vol. 113, pp. 502-507
  2. Bunker, R. S., Bailey, J. C. and Ameri, A. A., 1999, 'Heat Transfer and Flow on the First Stage Blade Tip of a Power Generation Gas Turbine Part I:Experimental Results,' ASME Paper No. 99-GT-169
  3. Ameri, A. A. and Bunker, R. S., 1999, 'Heat Transfer and Flow on the First Stage Blade Tip of a Power Generation Gas Turbine Part I:Simulation Results,' ASME Paper No. 99-GT-283
  4. Azad, Gm S., Han, Je-Chin, Teng, S. and Boyle, R. J. 2000, 'Heat Transfer and Pressure Distributions on a Gas Turbine Blade Tip,' ASME Paper No. 2000-GT-194
  5. Azad, Gm S., Han, Je-Chin and Boyle, R. J. 2000, 'Heat Transfer and Flow on the Squealer Tip of a Gas Turbine Blade,' ASME Paper No. 2000-GT-195
  6. Dunn, M. G. and Haldeman, C. W. 2000, 'Time-aeraged Heat Flux for a Recessed Tip, Lip, and Platform of a Transonic Turbine Blade,' ASME Paper No. 2000-GT-197
  7. 이동호, 김병기, 조형희, 1999, '분사각도변화에 따른 단일 막냉각홀 주위에서의 열/물질전달 및 막냉각효율 특성,' 대한기계학회논문집(B) 제22권 제10호 pp. 1434-1445
  8. Ambrose, D., Lawrenson, I. J. and Sparke, C. H. S., 1975, 'The Vapor Pressure of Naphthalene,' J. Chem. Thermo., Vol. 7, pp. 1173-1176
  9. Goldstein, R. J. and Cho, H. H., 1995, 'A Review of Mass Transfer Measurement Using Naphthalene Sublimation,' Experimental Thermal and Fluid Science, Vol. 10, pp. 416-434 https://doi.org/10.1016/0894-1777(94)00071-F
  10. Eckert, E. R. G., 1976, Analogies to Heat Transfer Processes, in Measurements in Heat Transfer, ed. Eckert, E. R. G. and Goldstein, R. J., pp. 397-423, Hemisphere Pub., New York
  11. Kline, S. J. and McClinetock, F., 1953, 'Describing Uncertainty in Single Sample Experiments,' Mech. Eng. Vol. 75, pp. 3-8