A numerical analysis of the flow in axial flow fans with skewed blades has been conducted to study the three-dimensional flow phenomena pertaining to this type of blade shape. The particular fans have a low pressure rise and are designed without stator. Initial studies focused on blades skewed in the circumferential direction, followed by investigations of blades swept in the direction of the blade chord. A Navier–Stokes code was used to investigate the flow. The simulation results of several fans were validated experimentally. The three-dimensional velocity field was measured in the fixed frame of reference with a triple sensor hot-film probe. Total pressure distribution measurements were performed with a fast response total pressure probe. The results were analyzed, leading to a design method for fans with swept blades. Forward swept fans designed accordingly exhibited good aerodynamic performance. The sound power level, measured on an acoustic fan test facility, improved.

1.
Abbott, I. H., and Von Doenhoff, A. E., 1959, Theory of Wing Sections, Dover Publications, New York.
2.
Beiler, M. G., 1996, “Untersuchung der dreidimensionalen Stro¨mung durch Axialventilatoren mit gekru¨mmten Schaufeln,” Dissertation Universita¨t Siegen, VDI-Verlag, Reihe 7, No, 298, Du¨sseldorf.
3.
Brown, N. A., 1977, “The Use of Skewed Blades for Ship Propellers and Truck Fans,” Noise and Fluids Eng., ASME, pp. 201–207.
4.
Carolus, T. H., and Scheidel, W., 1988, “Bemerkungen zum Einsatz schnella¨ufiger Axiallu¨fter in Motorku¨hlsystemen von Kraftfahrzeugen,” Mitteilungen Institut fu¨r Stro¨mungsmechanik, und Stro¨mungsmaschinen, Universita¨t’ Karlsruhe, Heft 39, pp. 19–26.
5.
Cordes, G., 1963, Stro¨mungstechnik der gasbeaufschlagten Axialturbine, Springer-Verlag, Dresden.
6.
Dejc, M. E., and Trojanovskij, B. M., 1973, Untersuchung und Berechnung axialer Turbinenstufen, VEB Verlag Technik, Berlin.
7.
Dejc
M. E.
,
Trojanovskij
B. M.
, and
Filippov
G. A.
,
1990
, “
Effective Way of Improving the Efficiency of Turbine Stages
,”
Thermal Engineering
, Vol.
37
, No.
10
, pp.
520
523
.
8.
DIN 24163, 1985, “Ventilatoren,” Teil 2, Beuth Verlag, Berlin.
9.
DIN EN 25136, 1994, “Bestimmung der von Ventilatoren in Kana¨len abgestrahlten Schalleistung,” Beuth Verlag, Berlin.
10.
Dixon, S. L., 1978, Fluid Mechanics, Thermodynamics of Turbomachinery, 3rd ed., Pergamon Press.
11.
Eck, B., 1972, Ventilatoren, 5th ed., Springer-Verlag, Berlin.
12.
Godwin, W. R., 1957, “Effect of Sweep on Performance of Compressor Blade Sections as Indicated by Swept-Blade Rotor, Unswept-Blade Rotor and Cascade Tests,” NACA TN 4062.
13.
Horlock, J. H., 1958, Axial Flow Compressors Fluid Mechanics and Thermodynamics, Butterworth Publications Limited, London.
14.
Ku¨chemann, D., 1952, “A Simple Method of Calculating the Span and Chordwise Loading on Straight and Swept Wings of Any Given Aspect Ratio at Subsonic Speeds,” Aeronautical Research Council, Reports and Memoranda No. 2935.
15.
Launder
B. E.
,
1989
, “
Second-Moment Closure and Its Use in Modelling Turbulent Industrial Flows
,”
International Journal for Numerical Methods in Fluids
, Vol.
9
, pp.
963
985
.
16.
Mohammad, K. P., and Raj, D. P., 1977, “Investigations on Axial Flow Fan Impellers With Forward Swept Blades,” ASME Paper No. 77-FE-1.
17.
Smith
L. H.
, and
Yeh
H.
,
1963
, “
Sweep and Dihedral Effects in Axial-Flow Turbomachinery
,”
ASME Journal of Basic Engineering
, Vol.
9
, pp.
401
416
.
18.
Smith
L. H.
,
1987
, “
Unducted Fan Aerodynamic Design
,”
ASME JOURNAL OF TURBOMACHINERY
, Vol.
109
, pp.
313
324
.
19.
TASCflow Theory Documentation, 1994, Version 2.3, Advanced Scientific Computing, Waterloo.
20.
Thwaites, B., 1960, Incompressible Aerodynamics, Clarendon Press, Oxford.
21.
Vavra, M. H., 1960, Aero-Thermodynamics and Flow in Turbomachines, Wiley, New York.
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