Back to results
US 7,540,354 B2Granted
Micro-perforated acoustic liner
AssigneeUnited Technologies Corporation
InventorsBruce L. Morin, Rudolph A. Ksiazkiewicz, Jr., Dennis Cicon
Life of this patent
Estimating the term…
Abstract
An example liner assembly includes a backing plate that supports a cellular structure covered by a perforated face sheet including a plurality of openings. Each of the plurality of openings is of a size determined to provide desired acoustic performance.
Claims17
A method of fabricating a noise attenuating liner comprising the steps of:
- a) supporting a cellular structure on a support backing;
- b) covering the cellular structure with a perforated face sheet, where the perforated face sheet includes a plurality of openings for communicating acoustic energy to the cellular structure;
- d) determining a range of percent open areas of the perforated face sheet based on selected upper and lower limits of a non-linearity factor and a resistance value;
- e) determining an opening size for each of the plurality of openings based on the selected upper and tower limits of the non-linearity factor and the resistance value that is no greater than ¼th a thickness of the perforated face sheet;
- f) generating a design range of percent open areas and hole diameters based on the determined range of percent open area and opening size;
- and
- g) forming the plurality of openings within the perforated sheet that includes openings with an opening size and percent open area within the generated design range.
4 more elements
A method of fabricating a perforated face sheet for a noise attenuation liner comprising the steps of:
- (a) specifying a desired thickness of the perforated face sheet;
- (b) determining a desired percent open area for the perforated face sheet based on a non-linearity factor and a value indicative of resistance to airflow;
- (c) determining an opening size based on the non-linearity factor and the value indicative of resistance to airflow;
- (d)forming a plurality of holes in the perforated face sheet including the determined opening size and percent open area, wherein a diameter of each of the plurality of openings is not greater than ¼th a thickness of the perforated face sheet.
1 more element
A noise attenuation liner assembly comprising
- a cellular structure disposed on a support backing;
- a perforated metal sheet including a plurality of openings affixed over the cellular structure on a side opposite the support backing, wherein an opening size for each of the plurality of openings and percent open area of the perforated metal sheet is determined based on a desired non-linearity factor and a factor indicative of resistance to flow.
Dependencies are inferred from the claim text.