Fan noise reduction using an adaptive helmholtz chamber
AssigneeLenovo Enterprise Solutions (Singapore) Pte. Ltd.
InventorsDaniel P. Kelaher, Kevin Perveiler
Life of this patent
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Abstract
A fan assembly includes a fan having an outlet side, a fan duct positioned at the fan outlet side, and a hollow cylindrical chamber positioned within the fan duct, wherein the chamber has two closed ends, a cylindrical side wall, and an inlet port. The dimensions of the chamber are determined to suppress one or more noise frequencies emitted by the fan. In one example, one or more dimensions of a chamber disposed in an outlet duct of an axial fan is automatically adjusted to suppress a noise frequency that is a function of a rotational speed of the axial fan.
Claims22
An apparatus, comprising:
- a fan having an outlet side;
- a fan duct positioned at the fan outlet side;
- and
- a hollow cylindrical chamber positioned within the fan duct, wherein the chamber has two closed ends, a cylindrical side wall, and an inlet port formed in the cylindrical side wall.
A method comprising:
- automatically adjusting one or more dimensions of a Helmholtz chamber disposed in an outlet duct of an axial fan to suppress a noise frequency that is a function of a rotational speed of the axial fan, wherein eddy currents induced by rotation of the axial fan are used to drive the adjustments in the one or more dimensions of the Helmholtz chamber as a function of the rotational speed of the axial fan.
An apparatus, comprising:
- a fan having an outlet side;
- a fan duct positioned at the fan outlet side;
- and
- a hollow cylindrical chamber positioned within the fan duct, wherein the chamber has two closed ends, a cylindrical side wall, and an inlet port, wherein one or more dimension of the chamber is varied in response to a change in fan rotational speed.
Dependencies are inferred from the claim text.