Abstract

In this paper, the effect of the inducer tip clearance is studied to understand its impact on the cavitating and noncavitating performance of centrifugal pumps. Helical inducers with constant pitch and with variable (progressive) pitch are considered. Computational fluid dynamics (CFD) simulations of a single stage pump are conducted on each inducer type to determine the cavitating (two-phase) and noncavitating (single-phase) performance for varying inducer tip clearance. The Rayleigh–Plesset cavitation model is used to understand the bubble dynamics under the assumptions of single fluid undergoing no thermal energy transfer between each phase. Experimental tests are conducted on a pump with the variable pitch inducer to determine the true performance in cavitating and noncavitating operating conditions. Experimental results are compared to the simulations to validate the accuracy of the proposed numerical modeling. Net positive suction head (NPSH) with 3% differential head drop is used as a criterion to identify the true cavitation performance of each inducer configuration. It is found that, as the inducer tip clearance increases, excessive back leakage and larger vortex recirculation occur at the tip location. This results in pressure loss within the inducer and, consequently, degrades the cavitation performance. In addition, the change in cavitation performance with the tip clearance is much more evident for variable pitch inducer geometries as compared to the constant pitch case. Furthermore, the impact on the noncavitating performance of inducer tip clearance is found to be minimal.

References

References
1.
Elliott Group,
2019
, “
In-tank Retractable—Ebara Cryodynamics
,” Elliott Group Cryodynamics, Sparks, NV, accessed July 17,
2019
, http://www.ebaracryo.com/in-tank-retractable/
2.
Jakobsen
,
J. K.
,
1971
, “
Liquid Rocket Engine Turbopump Inducers
,” National Aeronautics and Space Administration, Washington, DC, Technical Report No. SP-8052.
3.
Scheer
,
D. D.
,
Huppert
,
M. C.
,
Viteri
,
F.
, and
Farquhar
,
J.
,
1978
, “
Liquid Rocket Engine Axial-Flow Turbopumps
,” National Aeronautics and Space Administration, Washington, DC, Technical Report No. SP-8125.
4.
Kovich
,
G.
,
1970
, “
Cavitation Performance of 84 Deg Helical Inducer in Water and Hydrogen
,” National Aeronautics and Space Administration, Washington, DC, Technical Report, TN-D-7016.
5.
Japikse
,
D.
,
Marscher
,
W.
, and
Furst
,
R.
,
1997
,
Centrifugal Pump Design and Performance
,
Concepts ETI
,
Wilder, VT
.
6.
Japikse
,
D.
,
2001
, “
Overview of Industrial and Rocket Turbopump Inducer Design
,” Fourth International Symposium on Cavitation (
CAV2001
),
Pasadena, CA, June 20–23
.https://core.ac.uk/download/pdf/9412487.pdf
7.
Sutton
,
M.
,
1964
, “
Improving the Cavitation Performance of Centrifugal Pumps With Helical Inducers
,” BHR Group's, The Fluid Engineering Centre, Cranfield, UK, Technical Report No. TN814.
8.
Acosta
,
A. J.
,
1958
, “
An Experimental Study of Cavitating Inducers
,”
Second Office of Naval Research Symposium on Naval Hydrodynamics
, Washington, DC, Aug., pp.
533
557
. https://authors.library.caltech.edu/47405/
9.
Bakir
,
F.
,
Rey
,
R.
,
Gerber
,
A. G.
,
Belamri
,
T.
, and
Hutchinson
,
B.
,
2004
, “
Numerical and Experimental Investigations of the Cavitating Behavior of an Inducer
,”
Int. J. Rotating Mach.
,
10
(
1
), pp.
15
25
.10.1155/S1023621X04000028
10.
Watanabe
,
H.
, and Tsukamoto, H., 2011, “Design Optimization of Cryogenic Pump Inducer Considering Suction Performance and Cavitation Instability,”
ASME
Paper No. AJK2011-05010.10.1115/AJK2011-05010
11.
Ashihara
,
K.
, and
Goto
,
A.
, “
Effects of Blade Loading on Pump Inducer Performance and Flow Fields
,”
ASME
Paper No. FEDSM2002-31201.10.1115/FEDSM2002-31201
12.
Horiguchi
,
H.
,
Watanabe
,
S.
,
Tsujimoto
,
Y.
, and
Aoki
,
M.
,
2000
, “
Theoretical Analysis of Cavitation in Inducers With Unequal Blades With Alternate Leading Edge Cutback—Part I: Analytical Methods and the Results for Smaller Amounto of Cutback
,”
ASME J. Fluids Eng.
,
122
(
2
), pp.
412
418
.10.1115/1.483271
13.
Horiguchi
,
H.
,
Watanabe
,
S.
, and
Tsujimoto
,
Y.
,
2000
, “
Theoretical Analysis of Cavitation in Inducers With Unequal Blades With Alternate Leading Edge Cutback—Part II: Effects of the Amount of Cutback
,”
ASME J. Fluids Eng.
,
122
(
2
), pp.
419
424
.10.1115/1.483272
14.
Bakir
,
F.
,
Kouidri
,
S.
,
Noguera
,
R.
, and
Rey
,
R.
,
2003
, “
Experimental Analysis of an Axial Inducer Influence of the Shape of the Blade Leading Edge on the Performances in Cavitating Regimes
,”
ASME J. Fluids Eng.
,
125
(
2
), p.
293
.10.1115/1.1539872
15.
Guo
,
X.
,
Zhu
,
Z.
,
Cui
,
B.
, and
Shi
,
G.
,
2016
, “
Effects of the Number of Inducer Blades on the Anti-Cavitation Characteristics and External Performance of a Centrifugal Pump
,”
J. Mech. Sci. Technol.
,
30
(
7
), p.
3173
.10.1007/s12206-016-0510-1
16.
Campos-Amezcua
,
R.
,
Khelladi
,
S.
,
Mazur-Czerwiec
,
Z.
,
Bakir
,
F.
,
Campos-Amezcua
,
A.
, and
Rey
,
R.
,
2013
, “
Numerical and Experimental Study of Cavitating Flow Through an Axial Inducer Considering Tip Clearance
,”
J. Power Energy
,
227
(
8
), pp.
858
868
.
17.
Fu
,
X.
,
Yuan
,
J.
,
Yuan
,
S.
,
Pace
,
G.
, and
d'Agostino
,
L.
,
2017
, “
Effect of Tip Clearance on the Internal Flow and Hydraulic Performance of a Three-Bladed Inducer
,”
Int. J. Rotating Mach.
, 2017, p.
2329591
.
18.
Kim
,
C.
,
Kim
,
S.
,
Choi
,
C.-H.
, and
Baek
,
J.
,
2017
, “
Effects of Inducer Tip Clearance on the Performance and Flow Characteristics of a Pump in a Turbopump
,”
J. Power Energy
,
231
(
5
), pp. 847–857.10.1177/0957650913497357
19.
Hong
,
S.-S.
,
Kim
,
J.-S.
,
Choi
,
C.-H.
, and
Kim
,
J.
,
2006
, “
Effect of Tip Clearance on the Cavitation Performance of a Turbopump Inducer
,”
J. Propul. Power
,
22
(
1
), p.
174
.10.2514/1.11982
20.
Brennen
,
C. E.
,
1994
,
Hydrodynamics of Pumps
,
Concepts ETI
,
Norwich VT
.
21.
Zwart
,
P.
,
Gerber
,
A.
, and
Belamri
,
T.
,
2004
, “
A Two-Phase Flow Model for Predicting Cavitation Dynamics
,”
Fifth International Conference on Multiphase Flow
, Yokohama, Japan, May 30–June 3, Paper No.
152
.https://www.researchgate.net/publication/306205415_A_two-phase_flow_model_for_predicting_cavitation_dynamics
22.
ANSYS, 2018, “
ANSYS CFX Release 19.1, User Manual—Basic Solver Theory
,” ANSYS, Inc., Canonsburg, PA.
23.
ANSI
,
2012
, “Rotordynamic Pumps Guideline for NPSH Margin” Hydraulic Institute, Parsippany, NJ, Standard No. ANSI/IHI 9.6.1.
24.
ISO
,
2009
, “Centrifugal Pumps for Petroleum Petrochemical and Natural Gas Industries,” International Organization for Standardization, Geneva, Switzerland, Standard No. ISO 13709:2009.
25.
API,
2004, “Standard for Centrifugal Pumps for Petroleum, Petrochemical and Natural Gas Industries,” American Petroleum Institute, Washington, DC, Standard No. API 610.
26.
Rayleigh
,
L.
,
1917
, “
Pressure Developed in a Liquid During the Collapse of a Spherical Cavity
,”
Philos. Mag.
,
34
, pp.
94
98
.10.1080/14786440808635681
27.
Plesset
,
M. S.
,
1949
, “
The Dynamics of Cavitation Bubbles
,”
ASME J. Appl. Mech.
,
16
, pp.
277
282
.
28.
Mani
,
K. V.
,
Cervone
,
A.
, and
Hickey
,
J.-P.
,
2017
, “
Turbulence Modeling of Cavitating Flows in Liquid Rocket Turbopumps
,”
ASME J. Fluids Eng.
,
139
(
1
), p.
011301
.
29.
Betchel Corporation,
2019
,
“Corpus Christi Liquefaction Construction-Projects-Bechtel,” Bechtel Corporation, Reston, VA,
accessed July 17,
2017
, https://www.bechtel.com/projects/corpus-christi-liquefaction-project/
30.
Celik
,
I. B.
,
Ghia
,
U.
,
Roache
,
P. J.
,
Freitas
,
C. J.
,
Coleman
,
H.
, and
Raad
,
P. E.
,
2008
, “
Procedure for Estimation and Reporting of Uncertainty Due to Discretization in CFD Applications
,”
ASME J. Fluids Eng.
,
130
(
7
), p.
078001
.
31.
Escaler
,
X.
, and
Diaz
,
V. H. H.
,
2018
, “
Sensitivity Analysis of Zwart-Gerber-Belamri Model Parameters on the Numerical Simulation of Francis Runner Cavitation
,”
Tenth International Symposium on Cavitation (CAV2018)
, Baltimore, MD, May 14–16, pp.
911
914
.
You do not currently have access to this content.