Composite insulation for reducing broadband aircraft noise
AssigneeHarman International Industries, Incorporated
InventorsDonald Joseph Butts, Todd Suko
Life of this patent
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Abstract
A composite insulation is included between the skin of an aircraft and interior trim panels. The composite insulation includes multiple layers of micro-perforate material interspersed with layers of semi-rigid material. For a given thickness, the composite insulation provides superior transmission loss over a wide range of frequencies, including low frequencies, compared to conventional homogeneous insulation having the same thickness. Thus, the composite insulation reduces broadband noise within the cabin of an aircraft more effectively compared to conventional insulation.
Claims21
A composite insulation configured to reduce the amplitude of broadband vibrations, comprising:
- a first micro-perforate layer that includes a first plurality of perforations and is configured to absorb broadband sound energy;
- and
- a first semi-rigid layer that is coupled to the first micro-perforate layer and is configured to provide structural support to the first micro-perforate layer and to absorb broadband sound energy, wherein the first semi-rigid layer is composed of a felt material.
A structure, comprising:
- an outer layer;
- an inner layer;
- and
- an insulation layer disposed between the outer layer and the inner layer, comprising:
- a first micro-perforate layer that includes a first plurality of perforations and is configured to absorb broadband sound energy, and
- a first semi-rigid layer that is coupled to the first micro-perforate layer and is configured to provide structural support to the first micro-perforate layer and to absorb broadband sound energy, wherein the first semi-rigid layer is composed of a felt material.
(canceled)
A composite insulation configured to reduce the amplitude of broadband vibrations, comprising:
- a first micro-perforate layer that includes a first plurality of perforations and is configured to absorb broadband sound energy;
- a first semi-rigid layer having a first surface that is coupled to the first micro-perforate layer and is configured to provide structural support to the first micro-perforate layer and to absorb broadband sound energy;
- a second micro-perforate layer having a first surface that is coupled to a second surface of the first semi-rigid layer, wherein the second micro-perforate layer includes a second plurality of perforations and is configured to absorb broadband sound energy;
- and
- a second semi-rigid layer that is coupled to a second surface of the second micro-perforate layer and is configured to provide structural support to the second micro-perforate layer and to absorb broadband sound energy, wherein the first semi-rigid layer and the second semi-rigid layer are composed of a felt material.
Dependencies are inferred from the claim text.