This study assesses the effectiveness of modified blade-tip configurations in achieving passive noise control in industrial fans. The concepts developed here, which are based on the addition of end-plates at the fan-blade tip, are shown to have a beneficial effect on the fan aeroacoustic signature as a result of the changes they induce in tip-leakage-flow behavior. The aerodynamic merits of the proposed blade-tip concepts are investigated by experimental and computational studies in a fully ducted configuration. The flow mechanisms in the blade-tip region are correlated with the specific end-plate design features, and their role in the creation of overall acoustic emissions is clarified. The tip-leakage flows of the fans are analyzed in terms of vortex structure, chordwise leakage flow, and loading distribution. Rotor losses are also investigated. The modifications to blade-tip geometry are found to have marked effects on the multiple vortex behaviors of leakage flow as a result of changes in the near-wall fluid flow paths on both blade surfaces. The improvements in rotor efficiency are assessed and correlated with the control of tip-leakage flows produced by the modified tip end-plates.
Issue Section:
Flows in Complex Systems
Keywords:
acoustic emission,
aeroacoustics,
aerodynamics,
blades,
fans,
plates (structures),
rotors,
vortices
Topics:
Blades,
Fans,
Flow (Dynamics),
Leakage,
Noise (Sound),
Plates (structures),
Rotors,
Vortices,
Design,
Leakage flows
1.
Ganz
, U. W.
, Joppa
, P. D.
, and Scharpf
, D. F.
, 1998, “Boeing 18-inch Fan Rig Broadband Noise Test
,” NASA Report No. CR-1998–208704.2.
Fukano
, T.
, Takamatsu
, Y.
, and Kodama
, Y.
, 1986, “The Effects of Tip Clearance on the Noise of Low-Pressure Axial and Mixed Flow Fans
,” J. Sound Vib.
0022-460X, 105
, pp. 291
–308
.3.
Storer
, J. A.
, and Cumpsty
, N. A.
, 1991, “Tip Leakage Flow in Axial Compressors
,” ASME J. Turbomach.
0889-504X, 113
, pp. 252
–259
.4.
Furukawa
, M.
, Inoue
, M.
, Kuroumaru
, M.
, Saiki
, K.
, and Yamada
, K.
, 1999, “The Role of Tip Leakage Vortex Breakdown in Compressor Rotor Aerodynamics
,” ASME J. Turbomach.
0889-504X, 121
, pp. 469
–480
.5.
Fukano
, T.
, and Jang
, C.
, 2004, “Tip Clearance Noise of Axial Flow Fans Operating at Design and Off-Design Condition
,” J. Sound Vib.
0022-460X, 275
, pp. 1027
–1050
.6.
Jang
, C.
, Fukano
, T.
, and Furukawa
, M.
, 2003, “Effects of the Tip Clearance on Vortical Flow and Its Relation to Noise in an Axial Flow Fan
,” JSME Int. J., Ser. B
1340-8054, 46
, pp. 356
–365
.7.
Quinlan
, D. A.
, and Bent
, P. H.
, 1998, “High Frequency Noise Generation in Small Axial Flow Fans
,” J. Sound Vib.
0022-460X, 218
, pp. 177
–204
.8.
Cumpsty
, N. A.
, 1977, “A Critical Review of Turbomachinery Noise
,” ASME J. Fluids Eng.
0098-2202, 99
, pp. 278
–293
.9.
Wright
, S. E.
, 1976, “The Acoustic Spectrum of Axial Flow Machines
,” J. Sound Vib.
0022-460X, 45
(2
), pp. 165
–223
.10.
Wadia
, A. R.
, Szucs
, P. N.
, and Crall
, D. W.
, 1998, “Inner Workings of Aerodynamic Sweep
,” ASME J. Turbomach.
0889-504X, 120
, pp. 671
–682
.11.
Corsini
, A.
, and Rispoli
, F.
, 2004, “Using Sweep to Extend Stall-Free Operational Range in Sub-Sonic Axial Fan Rotors
,” Proc. Inst. Mech. Eng., Part A
0957-6509, 218
, pp. 129
–139
.12.
Takata
, H.
, and Tsukuda
, Y.
, 1977, “Stall Margin Improvement by Casing Treatment—Its Mechanism and Effectiveness
,” ASME J. Eng. Power
0022-0825, 99
, pp. 121
–133
.13.
Smith
, G. D. J.
, and Cumpsty
, N. A.
, 1984, “Flow Phenomena in Compressor Casing Treatment
,” ASME J. Eng. Gas Turbines Power
0742-4795, 106
, pp. 532
–541
.14.
Thompson
, D. W.
, King
, P. I.
, and Rabe
, D. C.
, 1998, “Experimental and Computational Investigation on Stepped Tip Gap Effects on the Flowfield of a Transonic Axial-Flow Compressor Rotor
,” ASME J. Turbomach.
0889-504X, 120
, pp. 477
–486
.15.
Jensen
, C. E.
, 1986, “Axial-Flow Fan
,” U.S. Patent No. 4,630,993.16.
Corsini
, A.
, Rispoli
, F.
, and Sheard
, A. G.
, 2008, “A Meridional Fan
,” Patent Application No. GB 0800582.9.17.
Longet
, C. M. L.
, 2003, “Axial Flow Fan With Noise Reducing Means
,” U.S. Patent 2003/0123987 A1.18.
Mimura
, M.
, 2003, “Axial Flow Fan
,” U.S. Patent No. 6,648,598 B2.19.
Uselton
, R. B.
, Cook
, L. J.
, and Wright
, T.
, 2005, “Fan With Reduced Noise Generation
,” U.S. Patent No. 2005/0147496 A1.20.
Corsini
, A.
, Perugini
, B.
, Rispoli
, F.
, Kinghorn
I.
, and Sheard
A. G.
, 2006, “Investigation on Improved Blade Tip Concept
,” ASME Paper No. GT2006–90592.21.
Corsini
, A.
, and Sheard
, A. G.
, 2007, “Tip End-Plate Concept Based on Leakage Vortex Rotation Number Control
,” J. Comput. Appl. Mech.
, 8
(1
), pp. 21
–37
1586-2070.22.
Corsini
, A.
, Rispoli
, F.
, and Sheard
, A. G.
, 2007, “Development of Improved Blade Tip Endplate Concepts for Low-Noise Operation in Industrial Fans
,” Proc. Inst. Mech. Eng., Part A
0957-6509, 221
, pp. 669
–681
.23.
Borello
, D.
, Corsini
, A.
, and Rispoli
, F.
, 2003, “A Finite Element Overlapping Scheme for Turbomachinery Flows on Parallel Platforms
,” Comput. Fluids
0045-7930, 32
(7
), pp. 1017
–1047
.24.
Corsini
, A.
, Rispoli
, F.
, and Santoriello
, A.
, 2005, ““A Variational Multi-Scale High-Order Finite Element Formulation for Turbomachinery Flow Computations
,” Comput. Methods Appl. Mech. Eng.
0045-7825, 194
(45–47
), pp. 4797
–4823
.25.
Powell
, A.
, 1963, “Mechanisms of Aerodynamic Sound Production
,” AGARD Report No. 466.26.
Powell
, A.
, 1964, “The Theory of Vortex Sound
,” J. Acoust. Soc. Am.
0001-4966, 36
, pp. 177
–195
.27.
Kinghorn
, I. R.
, and Millar
, S.
, 2005, FW-RDLab Report No. r9124.28.
Inoue
, M.
, Kuroumaru
, M.
, and Furukawa
, M.
, 1986, “Behavior of Tip Leakage Flow Behind an Axial Compressor Rotor
,” ASME J. Eng. Gas Turbines Power
0742-4795, 108
, pp. 7
–14
.29.
Spall
, R. E.
, Gatski
, T. B.
, and Grosch
, C. E.
, 1987, “A Criterion for Vortex Breakdown
,” Phys. Fluids
1070-6631, 30
(11
), pp. 3434
–3440
.30.
Uchida
, S.
, Nakamura
, Y.
, and Ohsawa
, M.
, 1985, “Experiments on the Axisymmetric Vortex Breakdown in a Swirling Air Flow
,” Trans. Jpn. Soc. Aeronaut. Space Sci.
0549-3811, 27
(78
), pp. 206
–216
.31.
Garg
, A. K.
, and Leibovich
, S.
, 1979, “Spectral Characteristics of Vortex Breakdown Flowfields
,” Phys. Fluids
1070-6631, 22
(11
), pp. 2053
–2064
.32.
Gbadebo
, S. A.
, Cumpsty
, N. A.
, and Hynes
, T. P.
, 2006, “Interaction of Tip Clearance Flow and Three-Dimensional Separations in Axial Compressors
,” ASME Paper No. GT2006–90071.33.
2000, BS 848-2.6:2000, ISO 10302:1996, Fans for General Purposes: Methods of Noise Testing.
34.
Leggat
, L. J.
, and Siddon
, T. E.
, 1978, “Experimental Study of Aeroacoustic Mechanism of Rotor-Vortex Interactions
,” J. Acoust. Soc. Am.
0001-4966, 64
, pp. 1070
–1077
.35.
Escudier
, M. P.
, and Zehnder
, N.
, 1982, “Vortex-Flow Regimes
,” J. Fluid Mech.
0022-1120, 115
, pp. 105
–121
.36.
Inoue
, M.
, and Furukawa
, M.
, 2002, “Physics of Tip Clearance Flow in Turbomachinery
,” ASME Paper No. FEDSM2002–31184.37.
Craft
, T. J.
, Launder
, B. E.
, and Suga
, K.
, 1996, “Development and Application of a Cubic Eddy-Viscosity Model of Turbulence
,” Int. J. Heat Fluid Flow
0142-727X, 17
, pp. 108
–155
.38.
Corsini
, A.
, and Rispoli
, F.
, 2005, “Flow Analyses in a High-Pressure Axial Ventilation Fan With a Non-Linear Eddy-Viscosity Closure
,” Int. J. Heat Fluid Flow
0142-727X, 26
, pp. 349
–361
.39.
Vad
, J.
, and Bencze
, F.
, 1998, “Three-Dimensional Flow in Axial Flow Fans of Non-Free Vortex Design
,” Int. J. Heat Fluid Flow
0142-727X, 19
(6
), pp. 601
–607
.40.
Khourrami
, M. R.
, and Choudari
, M.
, 2001, “A Novel Approach for Reducing Rotor Tip-Clearance Induced Noise in Turbofan Engines
,” AIAA Paper No. 2001-2148.41.
Tam
, C. K. W.
, 1994, “Jet Noise Generated by Large-Scale Coherent Motion
,” Aeroacoustics of Flight Vehicles: Theory and Practice
(Noise Sources
), H. H.
Hubbard
, ed., NASA Langley Research Center, Springer-Verlag
, Berlin
, Vol. I
, pp. 311
–390
.42.
Bianchi
, S.
, Sheard
, A. G.
, Kinghorn
, I. R.
, Corsini
, A.
, and Rispoli
, F.
, 2009, “Experimental Development of a Measurement Technique to Resolve the Radial Distribution of Fan Aero-Acoustic Emissions
,” Noise Control Eng. J.
0736-2501, July–August
.43.
Bianchi
, S.
, Corsini
, A.
, Rispoli
, F.
, and Sheard
, A. G.
, 2008, “Experimental Aeroacoustic Studies on Improved Tip Geometries for Passive Noise Signature Control in Low-Speed Axial Fan
,” ASME Paper GT2008–51057.44.
Sujudi
, D.
, and Haimes
, R.
, 1995, “Identification of Swirling Flow in 3-D Vector Field
,” AIAA Paper No. AIAA95-1715.45.
Burdsall
, E. A.
, and Urban
, R. H.
, 1973, “Fan-Compressor Noise: Prediction, Research and Reduction Studies
,” Paper No. FAA-RD-71-73.46.
Lighthill
, M. J.
, 1952, “On Sound Generated Aerodynamically. I: General Theory
,” Proc. R. Soc. London, Ser. A
1364-5021, 221
, pp. 564
–587
.47.
Lighthill
, M. J.
, 1954, “On Sound Generated Aerodynamically. II: Turbulence as a Source of Sound
,” Proc. R. Soc. London, Ser. A
0950-1207, 222
, pp. 1
–32
.48.
Arakawa
, C.
, Fleig
, O.
, Makoto
, I.
, and Masakazu
, S.
, 2005, “Numerical Approach for Noise Reduction of Wind Turbine Blade Tip With Earth Simulator
,” Journal of the Earth Simulator
, 2
, pp. 11
–33
1349-2667.49.
Senoo
, Y.
, 1991, “Mechanics on the Tip Clearance Loss of Impeller Blades
,” ASME J. Turbomach.
0889-504X, 113
, pp. 680
–685
.Copyright © 2009
by American Society of Mechanical Engineers
You do not currently have access to this content.
