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US 6,609,592 B2Granted
Noise attenuation panel
AssigneeShort Brothers PLC
InventorRobert Samuel Wilson
Life of this patent
Estimating the term…
Abstract
A noise attenuation panel used to attenuate noise in aircraft engines includes a cellular core and a facing sheet formed with an array of holes. The holes are laser drilled to provide: (i) hole size variation over the facing sheet; (ii) non-circular hole cross section; (iii) polygonal hole cross section; (iv) hole locations not contiguous with walls of the cellular core; and (v) inclined holes passing through the facing sheet in a direction inclined to the normal to the facing sheet.
Claims29
A method of manufacturing a noise attenuation panel which comprises:
- a cellular component part which:
- has a front face and a rear face and
- a cell defining wall structure which defines a multiplicity of cells between the front face and the rear face, and
- a facing component part which:
- has a front face and a rear face,
- extends across the ends of the cells of the cellular component part at the front face thereof with the rear face of the facing component part adjacent the front face of the cellular component part, and
- is provided with a multiplicity of holes which extend through the facing component part from the front face to the rear face to provide gaseous fluid communication between the cells of the cellular component part and the front face of the facing component part for the attenuation of noise generated by gaseous fluid flow over the surface of the front face of the facing component part,
- characterised in that:
- the method comprises producing, in a hole producing step, the multiplicity of holes through the facing component part in the form of an array of holes which pass through the component part from the rear face of the facing component part to the front face of the facing component part in a predetermined hole direction inclined to the normal to the front face.
6 more elements
A method of manufacturing a noise attenuation panel which comprises:
- a cellular component part which:
- has a front face and a rear face and
- a cell defining wall structure which defines a multiplicity of cells between the front face and the rear multiplicity of cells between the front face and the rear face and which terminate in end portions at the front face of the cellular component part, and a facing component part which:
- has a front face and a rear face,
- extends across the ends of the cells of the cellular component part at the front face thereof with the rear face of the facing component part adjacent the front face of the cellular component part, and
- is provided with a multiplicity of holes which extend through the facing component part from the front face to the rear face to provide gaseous fluid communication between the cells of the cellular component part and the front face of the facing component part for the attenuation of noise generated by gaseous fluid flow at the surface of the front face of the facing component part, and characterized in that:
- laser drilling is employed to drill the holes such that no holes are drilled at locations of the facing component part which in the assembled panel are contiguous with the end portions of the walls of the cell wall structure.
4 more elements
A method of manufacturing a noise attenuation panel which comprises:
- a cellular component part which:
- has a front face and a rear face and
- a cell defining wall structure which defines a multiplicity of cells between the front face and the rear face, and
- a facing component part which:
- has a front face and a rear face,
- extends across the ends of the cells of the cellular component part at the front face thereof with the rear face of the facing component part adjacent the front face of the cellular component part, and
- is provided with a multiplicity of holes which extend through the facing component part from the front face to the rear face to provide gaseous fluid communication between the cells of the cellular component part and the front face of the facing component part for the attenuation of noise generated by gaseous fluid flow at the surface of the front face of the facing component part,
- characterised in that:
- the facing component part is in the form of a fibre reinforced composite comprising a matrix component and a fibre reinforcing component embodied within the matrix component,
- the fibre reinforcing component comprises arrays of fibres in which the fibres of each array extend in a predetermined direction in the matrix and in which the predetermined direction of the fibres of each array is different from that of the fibres of each of the other arrays, and
- the holes in the facing component part are so produced as to have a polygonal cross-section with sides arranged parallel to the predetermined directions of the fibres of the arrays.
8 more elements
A noise attenuation panel which comprises:
- a cellular component part which:
- has a front face and a rear face and
- a cell defining wall structure which defines a multiplicity of cells between the front face and the rear face, and
- a facing component part which:
- has a front face and a rear face,
- extends across the ends of the cells of the cellular component part at the front face thereof with the rear face of the facing component part adjacent the front face of the cellular component part, and
- is provided with a multiplicity of holes which extend through the facing component part from the front face to the rear face to provide gaseous fluid communication between the cells of the cellular component part and the front face of the facing component part for the attenuation of noise generated by gaseous fluid flow at the surface of the front face of the facing component part,
- characterised in that:
- the facing component part is in the form of a fibre reinforced composite comprising a matrix component and a fibre reinforcing component embodied within the matrix component,
- the fibre reinforcing component comprises arrays of fibres in which the fibres of each array extend in a predetermined direction in the matrix and in which the predetermined direction of the fibres of each array is different from that of the fibres of each of the other arrays, and
- the holes in the facing component part have a polygonal cross-section with sides arranged parallel to the predetermined directions of the fibres of the arrays.
8 more elements
A method of manufacturing a noise attenuation panel which comprises:
- a cellular component part which:
- has a front face and a rear face and
- a cell defining wall structure which defines a multiplicity of cells between the front face and the rear face, and
- a facing component part which:
- has a front face and a rear face,
- extends across the ends of the cells of the cellular component part at the front face thereof with the rear face of the facing component part adjacent the front face of the cellular component part, and
- is provided with a multiplicity of holes which extend through the facing component part from the front face to the rear face to provide gaseous fluid communication between the cells of the cellular component part and the front face of the facing component part for the attenuation of noise generated by gaseous fluid flow at the surface of the front face of the facing component part,
- characterised in that:
- the method comprises producing, in a hole producing step, the multiplicity of holes through the facing component part in the form of an array of holes having at least one hole characteristic selected from the group consisting of:
- holes having a hole size which so varies over the facing component part as to provide optimum attenuating performance of the panel over a predetermined range of gaseous flow conditions at the front face of the facing component part
- holes having a non-circular hole cross-section which is so chosen as to provide optimum combined structural strength and attenuating performance of the panel
- holes having a predetermined hole direction inclined to the normal to the front face of the facing component part
- holes having no locations on the facing component part which in the assembled panel are contiguous with the walls of the cell defining wall structure, and
- holes having a polygonal cross-section.
11 more elements
A noise attenuation panel which comprises:
- a cellular component part which:
- has a front face and a rear face and
- a cell defining wall structure which defines a multiplicity of cells between the front face and the rear face, and
- a facing component part which:
- has a front face and a rear face,
- extends across the ends of the cells of the cellular component part at the front face thereof with the rear face of the facing component part adjacent the front face of the cellular component part, and
- is provided with a multiplicity of holes which extend through the facing component part from the front face to the rear face to provide gaseous fluid communication between the cells of the cellular component part and the front face of the facing component part for the attenuation of noise generated by gaseous fluid flow at the surface of the front face of the facing component part,
- characterised in that:
- the multiplicity of holes through the facing component part form an array of holes having at least one hole characteristic selected from the group consisting of:
- holes having a hole size which so varies over the facing component part as to provide optimum attenuating performance of the panel over a predetermined range of gaseous flow conditions at the front face of the facing component part
- holes having a non-circular hole cross-section which is so chosen as to provide optimum combined structural strength and attenuating performance of the panel
- holes having a predetermined hole direction inclined to the normal to the front face of the facing component part
- holes having no locations on the facing component part which in the assembled panel are contiguous with the walls of the cell defining wall structure, and
- holes having a polygonal cross-section.
11 more elements
Dependencies are inferred from the claim text.