This paper summarizes the main results sorted out from a design of experiment (DoE) based on a validated computational fluid dynamics (CFD). Several tip recessed geometries applied to an unshrouded impeller were considered in conjunction with two tip clearance levels. The computations show that recessed tip geometries have positive effects when considering high-flow coefficient values, while in part-load conditions the gain is reduced. Starting from the results obtained when studying tip cavities, a single rim tip squealer geometry was then analyzed: the proposed geometry leads to performance improvements for all the tested conditions considered in this work.

References

References
1.
Pampreen
,
R. C.
,
1973
, “
Small Turbomachinery Compressor and Fan Aerodynamics
,”
J. Eng. Power
,
95
(
3
), pp.
251
256
.
2.
Senoo
,
Y.
, and
Ishida
,
M.
,
1986
, “
Pressure Loss Due to the Tip Clearance of Impeller Blades in Centrifugal and Axial Blowers
,”
ASME J. Eng. Gas Turbines Power
,
108
(
1
), pp.
32
37
.
3.
Senoo
,
Y.
, and
Ishida
,
M.
,
1987
, “
Deterioration of Compressor Performance Due to Tip Clearance of Centrifugal Impellers
,”
ASME J. Turbomach.
,
109
(
1
), pp.
55
61
.
4.
Ishida
,
M.
,
Senoo
,
Y.
, and
Ueki
,
H.
,
1990
, “
Secondary Flow Due to the Tip Clearance at the Exit of Centrifugal Impellers
,”
ASME J. Turbomach.
,
112
(
1
), pp.
19
24
.
5.
Cumpsty
,
N.
,
2004
,
Compressor Aerodynamics
,
Krieger Publishing
,
Malabar, FL
.
6.
Booth
,
T.
,
Dodge
,
P.
, and
Hepworth
,
H.
,
1982
, “
Rotor-Tip Leakage Part I: Basic Methodology
,”
ASME J. Eng. Power
,
104
(
1
), pp.
154
161
.
7.
Ameri
,
A.
,
Steinthorsson
,
E.
, and
Rigby
,
D. L.
,
1998
, “
Effect of Squealer Tip on Rotor Heat Transfer and Efficiency
,”
ASME J. Turbomach.
,
120
(
4
), pp.
753
759
.
8.
Camci
,
C.
,
Dey
,
D.
, and
Kavurmacioglu
,
L.
,
2003
, “
Tip Leakage Flows Near Partial Squealer Rims in an Axial Flow Turbine Stage
,”
ASME
Paper No. GT2003-38979.
9.
Zhou
,
C.
, and
Hodson
,
H.
,
2009
, “
The Tip Leakage Flow of an Unshrouded High Pressure Turbine Blade With Tip Cooling
,”
ASME
Paper No. GT2009-59637.
10.
Patel
,
K. V.
,
1980
, “
Research on a High Work Axial Gas Generator Turbine
,” SAE Paper No. 800618.
11.
Schabowski
,
Z.
, and
Hodson
,
H.
,
2007
, “
The Reduction of Over Tip Leakage Loss in Unshrouded Axial Turbines Using Winglets and Squealers
,”
ASME
Paper No. GT2007-27623.
12.
Bunker
,
R. S.
,
2004
, “
Blade Tip Heat Transfer and Cooling Design
,”
Turbine Blade Tip Design and Tip Clearance Treatment
(VKI Lecture Series),
von Karman Institute
,
Rhode-St-Genèse, Belgium
.
13.
Jung
,
Y.
,
Choi
,
M.
,
Park
,
J.
, and
Baek
,
J.
,
2013
, “
Effects of Recessed Blade Tips on the Performance and Flow Field in a Centrifugal Compressor
,”
Proc. Inst. Mech. Eng., Part A
,
24
(
2
), pp.
157
166
.
14.
Toni
,
L.
,
Ballarini
,
V.
,
Cioncolini
,
S.
,
Persico
,
G.
, and
Gaetani
,
P.
,
2010
, “
Unsteady Flow Field Measurements in an Industrial Centrifugal Compressor
,”
39th Turbomachinery Symposium
, pp.
49
58
.https://pdfs.semanticscholar.org/1f92/34c5ea0c36861a9365632e546eff95ee0559.pdf
15.
Bianchini
,
A.
,
Ferrara
,
G.
,
Ferrari
,
L.
,
Ballarini
,
V.
,
Bianchi
,
L.
,
Tapinassi
,
L.
, and
Toni
,
L.
,
2012
, “
Effects Due to the Temperature Measurement Section on the Performance Estimation of a Centrifugal Compressor Stage
,”
ASME J. Eng. Gas Turbines Power
,
134
(3), p. 032402.
16.
Guidotti
,
E.
,
Tapinassi
,
L.
,
Toni
,
L.
,
Bianchi
,
L.
,
Gaetani
,
P.
, and
Persico
,
G.
,
2011
, “
Experimental and Numerical Analysis of the Flow Field in the Impeller of a Centrifugal Compressor Stage at Design Point
,”
ASME
Paper No. GT2011-45036.
17.
Andreini
,
A.
, and
Da Soghe
,
R.
,
2012
, “
Numerical Characterization of Aerodynamic Losses of Jet Arrays for Gas Turbine Applications
,”
ASME J. Eng. Gas Turbines Power
,
134
(5), p. 052504.
18.
Da Soghe
,
R.
, and
Andreini
,
A.
,
2013
, “
Numerical Characterization of Pressure Drop for Turbine Casing Impingement Cooling System
,”
ASME J. Turbomach.
,
135
(3), p.
031017
.
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