• Title/Summary/Keyword: 팁누설유동

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Effects of Pressure-Side Winglet at an Elevation of Tip Surface on the Tip-Leakage Flow and Aerodynamic Loss Downstream of a Turbine Blade Equipped with Pressure-Side Squealer Tip (압력면익단소익이 터빈 동익 압력면스퀼러팁 하류의 팁누설유동 및 압력손실에 미치는 영향)

  • Cheon, Joo Hong;Lee, Sang Woo
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.40 no.10
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    • pp.645-651
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    • 2016
  • Effects of pressure-side winglet width on the tip leakage flow and aerodynamic loss downstream of a turbine blade with a pressure-side squealer rim have been investigated for the tip gap-to-span ratio of h/s = 1.36%. The pressure-side squealer has a fixed height-to-span ratio of $h_p/s=3.75%$ and the pressure-side winglet, which is installed at an elevation of tip surface, has width-to-pitch ratios of w/p = 2.64%, 5.28%, 7.92% and 10.55%. The results show that with increasing w/p, aerodynamic loss in the passage vortex region decreases, whereas that in the leakage flow region increases. As a result, the mass-averaged loss coefficient all over the measurement plane tends to decrease minutely with the increment of w/p. It is concluded that the pressure-side winglet for the pressure-side squealer tip can hardly contribute to the tip-leakge loss reduction.

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;Kang, Dong Bum;Lee, Sang Woo
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.38 no.5
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    • pp.399-406
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    • 2014
  • 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.

Measurement of Thermal Load in the Tip-Clearance Region of a Rotor Surface (팁간극 영역에서의 동익 표면 열부하 측정)

  • Lee, Sang-Woo;Kwon, Hyun-Goo;Park, Jin-Jae
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.187-192
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    • 2003
  • The heat (mass) transfer characteristics in the tip-leakage flow region of a high-turning first-stage turbine rotor blade has been investigated by employing the naphthalene sublimation technique. The heat transfer data in the tip-leakage flow area for the tip clearance-to-span ratio, h/s, of 2.0% are compared with those in endwall three-dimensional flow region without tip clearance (h/s = 0.0 %). The result shows that the thermal load in the tip-leakage flow region for h/s = 2.0% is more severe than that in the endwall flow region for h/s = 0.0%. The thermal loads even at the leading and trailing edges for h/s = 2.0% are found larger than those for h/s = 0.0%. The tip-leakage flow results in heat transfer augmentations near the tip on both pressure and suction sides in comparison with the mid-span results.

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Heat(Mass) Transfer Characteristics in the Tip-Leakage Flow Region of a High-Turning Turbine Rotor Blade (회전각이 큰 터빈 동익 누설유동 영역에서의 열(물질)전달 특성)

  • Lee, Sang-Woo;Kwon, Hyun-Goo
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.28 no.5
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    • pp.535-544
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    • 2004
  • The heat (mass) transfer characteristics in the tip-leakage flow region of a high-turning first-stage turbine rotor blade has been investigated by employing the naphthalene sublimation technique. The heat transfer data in the tip-leakage flow area for the tip clearance-to-span ratio, h/s, of 2.0% are compared with those in endwall three-dimensional flow region without tip clearance (h/s : 0.0 %). The result shows that the thermal load in the tip-leakage flow region for h/s = 2.0% is more severe than that in the endwall flow region for h/s : 0.0%. The thermal loads even at the leading and trailing edges for h/s = 2.0% are found larger than those for h/s = 0.0%. The tip-leakage flow results in heat transfer augmentations near the tip on both pressure and suction sides in comparison with the mid-span results.

Effects of Incidence on Aerodynamic Losses in the Tip-Leakage Flow Region of a High-Turning Turbine Rotor Blade (입사각이 터빈 동익 팁누설유동 영역에서의 압력손실에 미치는 영향)

  • Chae, Byoung-Joo;Lee, Sang-Woo
    • The KSFM Journal of Fluid Machinery
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    • v.13 no.2
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    • pp.41-47
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    • 2010
  • The effect of incidence angle on the three-dimensional flow and aerodynamic loss in the tip leakage flow region downstream of a turbine rotor cascade has been investigated for two tip gap-to-chord ratios of h/c=0.0% (no tip gap) and 2.0%. The incidence angle is changed to be $i=-10^{\circ}$, $0^{\circ}$, and $5^{\circ}$. The results show that for $i=5^{\circ}$, secondary flows including the passage vortex are intensified noticeably, and there is a strong interaction between the passage and tip leakage vortices. For $i=-10^{\circ}$, however, the passage vortex is weakened significantly, so that there exists only a strong leakage-jet-like secondary flows near the casing wall. For h/c=0.0% and 2.0%, aerodynamic loss tends to increase with increasing i from $-10^{\circ}$ to $5^{\circ}$. A small increment of i in its positive incidence range results in a remarkable aerodynamic loss increase, while increasing i in the negative incidence range leads to a small change in the aerodynamic loss generation.