Fluid reaction surfaces (i.e. – impellers) – Specific blade structure – Coating – specific composition or characteristic
Patent
1995-08-31
1997-02-11
Lopez, F. Daniel
Fluid reaction surfaces (i.e., impellers)
Specific blade structure
Coating, specific composition or characteristic
416241R, 415119, F04D 2938
Patent
active
056014104
ABSTRACT:
An air moving device such as an axial cooling fan comprises a rotatable shaft assembly and a plurality of fan blades coupled to the rotatable shaft assembly, each of the fan blades having a trailing edge when the rotatable shaft assembly is rotated in a given direction. In accordance with one illustrative embodiment of the invention, at least one of the fan blades has a sound reducing material attached thereto alongside the trailing edge thereof. The sound reducing material reduces aeroacoustic noise by reducing the aerodynamic effect that occurs when turbulence produced by the pressure differential between the two sides of one blade comes into contact either with the trailing edge of the given blade which created it, or, more significantly, with the following blade, at or near that blade's trailing edge. In various embodiments the sound reducing material may comprise felt, loops from a hook-and-loop-type fastener such as that sold under the VELCRO trademark, or a small piece of fiberglass, cotton or wool batting. In one illustrative embodiment, the sound reducing material is advantageously attached to the fan blade on the high pressure side thereof.
REFERENCES:
patent: 3275082 (1966-09-01), Stark
W. K. Blake, "Mechanics of Flow-Induced Sound And Vibration," Complex Flow-Structure Interactions Academic Press, Inc., vol. II, 1986, pp. 782-806.
T. F. Brooks et al., "Trailing Edge Noise Prediction From Measure Surface Pressures," Journal of Sound and Vibration, 1981, 78(1), pp. 69-117.
D-I.F. Kameler et al, "Experimental Investigation Of Tip Clearance Noise In axial Flow Machines," Proc. DGLR/ACAA-Aeroacoustics Conf., pp. 92-02-40, 250-259.
J. E. Ffowcs Williams et al, "Aerodynamic Sound Generation By Turbulent Flow In The Vicinity Of A Scattering half Plane," J. Fluid Mech., 1970, vol. 10, part 4, pp. 657-670.
R. K. Amiet, "Noise Due To Turbulent Flow Past A Trailing Edge," Journal of Sound and Vibration, 1976, 47(3), pp. 387-393.
R. E. Longhouse, "Control Of Tip-Vortex Noise Of Axial Flow Fans By Rotating Shrouds," Journal of Sound and Vibration, 1978, 58(2), pp. 201-214.
Brown Kenneth M.
Lopez F. Daniel
Lucent Technologies - Inc.
Sgantzos Mark
LandOfFree
Fan having blades with sound reducing material attached does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Fan having blades with sound reducing material attached, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fan having blades with sound reducing material attached will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-337258