This paper presents an experimental investigation of effects of grooved tip clearances on the flow field of a compressor cascade. The tests were performed in a low-speed large-scale cascade, respectively, with two tip-clearance configurations, including the flat tip and the grooved tip with a chordwise channel on the blade top. The flow field at 10% chord downstream from the cascade trailing edge was measured at four incidence angles using a mini five-hole pressure probe. The static pressure distribution was measured on the tip endwall. The results show that the pressure gradient from the pressure side to the suction side on the blade tip is reduced due to the existence of the channel. As a result, the leakage flow is weakened. The high-blockage and high-loss region caused by the leakage flow is narrower with the grooved tip. In the meantime, the leakage flow migrates to lower span-wise position. The combined result is that the flow capacity in the tip region is improved at the incidence angles of 0 deg and 5 deg with the grooved tip. However, the loss is slightly greater than that with the flat tip at all the incidence angles.

References

References
1.
Booth
,
T. C.
,
Dodge
,
P. R.
, and
Hepworth
,
H. K.
, 1981, “
Rotor-Tip Leakage: Part I-Basic Methodology
,” ASME Paper No. 81-GT-71.
2.
Wadia
,
A. R.
, and
Booth
,
T. C.
, 1981, “
Rotor-Tip Leakage: Part II-Design Optimization through Viscous Analysis and Experiment
,” ASME Paper No. 81-GT-72.
3.
Bindon
,
J. P
, and
Morphis
,
G.
, 1992, “
The Development of Axial Turbine Leakage Loss For Two Profiled Tip Geometries Using Linear Cascade Data
,”
ASME J. Turbomach.
,
114
, pp.
198
203
.
4.
Morphis
,
G.
, and
Bindon
,
J. P.
, 1994,“
The Performance of a Low Speed One and A Half Stage Axial Turbine with Varying Rotor Tip Clearance and Tip Gap Geometry
,” ASME Paper No. 94-GT-481.
5.
Heyes
,
F. J. G.
,
Hodson
,
H. P.
, and
Dailey
,
G. M.
, 1992, “
The Effect of Blade Tip Geometry on the Tip Leakage Flow in Axial Turbine Cascades
,”
ASME J. Turbomach.
,
114
, pp.
643
651
.
6.
Dey
,
D.
, and
Camci
,
C.
, 2001, “
Aerodynamic Tip Desensitization of an Axial Turbine Rotor Using Tip Platform Extensions
,” ASME Paper No. GT-2001-0484.
7.
Camci
,
C.
,
Dey
,
D.
, and
Levent
,
K.
, 2003, “
Tip Leakage Flows near Partial Squealer Rims in an Axial Flow Turbine Stage
,” ASME Paper No. GT2003-38979.
8.
Ameri
,
A. A.
, 2001, “
Heat Transfer and Flow on the Blade Tip of a Gas Turbine Equipped With a Mean-Camberline Strip
,”
ASME J. Turbomach.
,
123
, pp.
704
708
.
9.
Sumanta
,
A.
, 2003, “
Numerical Study of Flow and Heat Transfer on a Blade Tip with Different Leakage Reduction Strategies
,” ASME Paper No. GT2003-38617.
10.
Saha
,
A. K.
Sumanta
,
A.
Chander
,
P.
, and
Ron
,
B.
, 2003, “
Blade Tip Leakage Flow and Heat Transfer with Pressure-Side Winglet
,” ASME Paper No. GT2003-38620.
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