Transactions of the Korean Society of Mechanical Engineers B (대한기계학회논문집B)

The Korean Society of Mechanical Engineers (대한기계학회)
권호 표지
DOI QR코드

DOI QR Code

Three-Dimensional Flow and Aerodynamic Loss in the Tip-Leakage Flow Region of a Turbine Blade with Pressure-Side Winglet and Suction-Side Squealer

압력면윙렛/흡입면스퀼러형 터빈 동익 팁누설영역에서의 3차원유동 및 압력손실

  • Cheon, Joo Hong (Dept. of Mechanical Engineering, Kumoh Nat'l Institute of Technology) ;
  • Kang, Dong Bum (Dept. of Mechanical Engineering, Kumoh Nat'l Institute of Technology) ;
  • Lee, Sang Woo (Dept. of Mechanical Engineering, Kumoh Nat'l Institute of Technology)
  • 천주홍 (금오공과대학교 기계공학과) ;
  • 강동범 (금오공과대학교 기계공학과) ;
  • 이상우 (금오공과대학교 기계공학과)
  • Received : 2013.09.09
  • Accepted : 2014.03.12
  • Published : 2014.05.01
Download PDF
⟨ Previous Next ⟩

Abstract

Three-dimensional flow and aerodynamic loss in the tip-leakage flow region of a turbine blade equipped with both a pressure-side winglet and a suction-side squealer have been measured for the tip gap-to-span ratio of h/s = 1.36%. The suction-side squealer has a fixed height-to-span ratio of $h_s/s$ = 3.75% and the pressure-side winglet has width-to-pitch ratios of w/p = 2.64%, 5.28%, 7.92% and 10.55%. The results are compared with those for a plane tip and for a cavity squealer tip of $h_{ps}/s$ = 3.75%. The present tip delivers lower loss in the passage vortex region but higher loss in the tip-leakage vortex region, compared to the plane tip. With increasing w/p, its mass-averaged loss tends to be reduced. Regardless of w/p, the present tip provides lower loss than the plane tip but higher loss than the cavity squealer tip.

본 연구에서는 압력면윙렛/흡입면스퀼러형 터빈 동익 팁에 대하여 익렬 하류에서 3차원 유동 및 압력손실을 측정하였다. 팁간극비 h/s = 1.36%에 대하여, 흡입면스퀼러의 높이는 $h_s/s$ = 3.75%로 일정하게 유지하고, 압력면윙렛의 폭은 w/p = 2.64%, 5.28%, 7.92%, 10.55% 등으로 변화시키면서 실험을 수행하였다. 그 결과, 본 연구의 팁은 평면팁 대비 통로와류 영역에서 압력손실의 저감 효과가 매우 뛰어났지만, 팁누설와류 영역에서는 오히려 압력손실을 크게 증가시켰다. 본 연구의 질량평균 압력손실은 평면팁에 비해 크게 낮았지만, 전면스퀼러팁보다는 더 크게 나타났다. 압력면윙렛의 폭이 증가할수록 질량평균 압력손실은 감소하는 경향을 보였다.

Keywords

References

  1. Lee, S. W., Kim, S. U. and Kim, K. H., 2012, "Aerodynamic Performance of Winglets Covering the Tip Gap Inlet in a Turbine Cascade," International Journal of Heat and Fluid Flow, Vol. 34, pp. 36-46. https://doi.org/10.1016/j.ijheatfluidflow.2011.11.008
  2. Bindon, J. P., 1989, "The Measurement and Formation of Tip Clearance Loss," ASME Journal of Turbomachinery, Vol. 111, pp. 257-263. https://doi.org/10.1115/1.3262264
  3. Yamamoto, A., 1989, "Endwall Flow/Loss Mechanism in a Linear Turbine Cascade with Blade Tip Clearance," ASME Journal of Turbomachinery, Vol. 111, pp. 264-274. https://doi.org/10.1115/1.3262265
  4. Lee, S. W., Moon, H. S. and Lee, S. E., 2009, "Tip Gap Height Effects on Flow Structure and Heat/Mass Transfer over Plane Tip of a High-Turning Turbine Rotot Blade," International Journal of Heat and Fluid Flow, Vol. 30, pp. 198-210. https://doi.org/10.1016/j.ijheatfluidflow.2008.12.009
  5. Lee, S. W. and Chae, B. J., 2008, "Effects of Squealer Rim Height on Aerodynamic Losses Downstream of a High-Turning Turbine Rotor Blade," Experimental Thermal and Fluid Science, Vol. 32, pp. 1440-1447. https://doi.org/10.1016/j.expthermflusci.2008.03.004
  6. Lee, S. W. and Choi, M. Y., 2010, "Tip Gap Height Effects on the Aerodynamic Performance of a Cavity Squealer Tip in a Turbine Cascade in Comparison with Plane Tip Results: Part 2-Aerodynamic Loss," Experiments in Fluids, Vol. 49, pp. 713-723. https://doi.org/10.1007/s00348-010-0849-5
  7. Lee, S. E., Lee S. W. and Kwak, H. S., 2011, "Tip Leakage Aerodynamics over Stepped Squealer Tips in a Turbine Cascade," Experimental Thermal and Fluid Science, Vol. 35, pp. 135-145. https://doi.org/10.1016/j.expthermflusci.2010.08.014
  8. Li, W., Jiang, H., Zhang, Q, and Lee, S. W., 2013, "Squealer Tip Leakage Flow Characteristics in Transonic Condition," ASME Journal of Engineering for Gas Turbine and Power (in Press), ASME Paper GT2013-95283.
  9. O'Dowd, D. O., Zhang, Q., He, L., Oldfield, M. L. G., Ligrani, P. M., Cheong, B. C. Y. and Tibbott, I., 2011, "Aerothermal Performance of a Winglet at Engine Representative Mach and Reynolds Numbers," ASME Journal of Turbomachinery, Vol. 133, pp. 041026-1-041026-8. https://doi.org/10.1115/1.4003055
  10. Papa, M., Goldstein, R. J. and Gori, F., 2003, "Effects of Geometry and Tip Clearance on the Mass/Heat Transfer from a Large-Scale Gas Turbine Blade," ASME Journal of Turbomachinery, Vol. 125, pp. 90-96. https://doi.org/10.1115/1.1529190
  11. Treaster, A. L. and Yocum, A. M., 1979, "The Calibration and Application of Five-Hole probes," ISA Transactions, Vol. 18, pp. 23-34.
  12. Abernethy, R. B., Benedict, R. P. and Dowdell, R. B., 1985, "ASME Measurement Uncertainty," ASME Journal of Fluids Engineering, Vol. 107, pp. 161-164. https://doi.org/10.1115/1.3242450