Rotary kinetic fluid motors or pumps – With sound or vibratory wave absorbing or preventing means...
Patent
1976-12-02
1978-08-01
Husar, C. J.
Rotary kinetic fluid motors or pumps
With sound or vibratory wave absorbing or preventing means...
137 151, 181222, F04D 2966
Patent
active
041040023
ABSTRACT:
An acoustic duct such as a jet engine fan duct is lined with a plurality of circumferentially spaced strips of sound-absorbing materials which extend helically about the duct axis and which are effective to scatter spinning mode acoustic pressure fields to higher order attenuating modes for improved noise suppression. To maximize noise reduction, the pitch angle of the helix may be aligned to the direction of the wave front generated by the first stage rotor blades of a fan or compressor disposed in the duct when operating at a supersonic velocity relative to the incoming airstream. Alternate strips may be tuned to different frequencies and/or be separated by untreated strips.
REFERENCES:
patent: 2805730 (1957-09-01), Applegate
patent: 3508838 (1970-04-01), Martenson
patent: 3542152 (1970-11-01), Adamson et al.
patent: 3692141 (1972-09-01), Labussiere
patent: 3830335 (1974-08-01), Zorumski
patent: 3890060 (1975-06-01), Lipstein
patent: 3937590 (1976-02-01), Mani
patent: 3947148 (1976-03-01), Holt
General Electric Company
Husar C. J.
Lawrence Derek P.
Policinski Henry J.
LandOfFree
Spiral strip acoustic treatment does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Spiral strip acoustic treatment, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Spiral strip acoustic treatment will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1977253