The KSFM Journal of Fluid Machinery (한국유체기계학회 논문집)

Korean Society for Fluid machinery (한국유체기계학회)
권호 표지
DOI QR코드

DOI QR Code

Three-Dimensional Flow and Aerodynamic Loss Downstream of Turbine Rotor Blade with a Cutback Cavity Squealer Tip

터빈 동익 컷백스퀼러팁 하류에서의 3차원 유동 및 압력손실

  • 김선웅 (금오공과대학교 기계공학부 대학원) ;
  • 이상우 (금오공과대학교 기계공학부)
  • Received : 2010.10.28
  • Accepted : 2011.01.20
  • Published : 2011.02.01
Download PDF
⟨ Previous Next ⟩

Abstract

The effect of channel cutback 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-to-chord ratio of $h_{st}/c$ = 5.51% and h/c = 2.0% respectively. The cutback length-to-camber ratio is changed to be $CB/c_c$ = 0.0, 0.1, 0.2 and 0.3. The results show that longer cutback delivers not only stronger secondary flow but also higher aerodynamic loss in the tip leakage vortex region, meanwhile it leads to lower aerodynamic loss in the passage vortex region. The discharge of cavity fluid through the cutback opening provides a beneficial effect in the reduction of aerodynamic loss, whereas there also exists a side effect of aerodynamic loss increase due to local wider tip gap near the trailing edge. With increasing $CB/c_c$ from 0.0 to 0.3, the aerodynamic loss coefficient mass-averaged all over the measurement plane tends to increase slightly.

Keywords

References

  1. Cohen, H., Rogers, G. F. C., and Saravanamuttoo, H.I. H., 1996, Gas Turbine Theory, Longman GroupLimited, Essex.
  2. Bindon, J. P., 1989, “The Measurement and Formationof Tip Clearance,” ASME Journal of Turbomachinery,Vol. 111, pp. 257-263. https://doi.org/10.1115/1.3262264
  3. Yamamoto, A., 1989, “Endwall Flow/Loss Mechansmin a Linear Turbine Cascade With Vlade Tip Clearance,”ASME Journal of Turbomachinery, Vol. 111, pp.264-275. https://doi.org/10.1115/1.3262265
  4. Lee, S. W., Moon, H. S., and Lee, S. E., 2009, “TipGap Height Effects on Flow Structure and Heat/MassTransfer over Plane Tip of a High-Turning TurbineRotor Blade,” International Journal of Heat and FluidFlow, Vol. 30, pp. 198-210. https://doi.org/10.1016/j.ijheatfluidflow.2008.12.009
  5. Key, N., and Arts, T., 2006, “Comparison of TurbineTip Leakage Flow for Flat Tip and Squealer TipGeometries at High Speed Conditions,” ASME Journalof Turbomachinery, Vol. 128, pp. 213-220. https://doi.org/10.1115/1.2162183
  6. Lee, S. W. and Chae, B. J., 2008, “Effects of SquealerRim Height on Aerodynamic Losses Downstream of aHigh-Turning Turbine Rotor Blade,” ExperimentalThermal and Fluid Science, Vol. 32, pp. 1440-1447. https://doi.org/10.1016/j.expthermflusci.2008.03.004
  7. Lee, S. W. and Kim, S. U., 2010, “Tip Gap Height Effects on the Aerodynamic Performance of CavitySquealer Tip in a Turbine Cascade in Comparisonwith Plane Tip Results-Part 1: Tip Gap Flow Structure,”Experiments in Fluids, Vol. 49, pp. 1039-1051. https://doi.org/10.1007/s00348-010-0848-6
  8. Lee, S. W. and Choi, M. Y., 2010, “Tip Gap HeightEffects on the Aerodynamic Performance of CavitySquealer Tip in a Turbine Cascade in Comparisonwith Plane Tip Results-Part 2: Aerodynamic Losses,”Experiments in Fluids, Vol. 49, pp. 713-723. https://doi.org/10.1007/s00348-010-0849-5
  9. Lee, S. E., Lee, S. W., and Kwak, H. S., 2011, “TipLeakage Aerodynamics over Stepped Squealer Tips in aTurbine Cascade,” Experimental Thermal and FluidScience, Vol. 35, pp. 135-145. https://doi.org/10.1016/j.expthermflusci.2010.08.014
  10. Mhetras, S., Narzary, D., Gao, Z., and Han, J-C, 2008,“Effect of a Cutback Squealer and Cavity Depth onFilm-Cooling Effectiveness on a Gas Turbine BladeTip,” ASME Journal of Turbomachinery, Vol. 130, pp.021002-1-021002-13. https://doi.org/10.1115/1.2776949
  11. Treaster, A. L. and Yocum, A. M., 1979, “The Calibration and Application of Five-Hole probes,” ISATransactions, Vol. 18, pp. 23-34.
  12. Lee, S. W. and Jun S. B., 2005, “Reynolds NumberEffects on the Non-Nulling Calibration of a Cone-Type Five-Hole Probe for Turbomachinery Applications,”Journal of Mechanical Science and Technology, Vol.19, pp. 1632-1648. https://doi.org/10.1007/BF03023940
  13. Lee, S. W. and Yoon, T. J., 1999, “An Investigation ofWall-Proximity Effect Using a Typical Large-ScaleFive-Hole Probe,” KSME International Journal, Vol.13, pp. 273-285. https://doi.org/10.1007/BF02970486
  14. Abernethy, R. B., Benedict, R. B., and Dowdell, R. B.,1985, “ASME Measurement Uncertainty,” ASMEJournal of Fluids Engineering, Vol. 107, pp. 161-164. https://doi.org/10.1115/1.3242450
  15. Lee, S. W., and Park, J. J., 2009, “Effects of IncidenceAngle on Endwall Convective Transport Within aHigh-Turning Turbine Rotor Passage,” InternationalJournal of Heat and Mass Transfer, Vol. 52, pp.5922-5931. https://doi.org/10.1016/j.ijheatmasstransfer.2009.07.015