Enhanced performance fan with the use of winglets
AssigneeHewlett-Packard Company
InventorChristian L Belady
Life of this patent
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Abstract
Small winglets placed at the outer end of each fan blade substantially reduce the vortices created in conventional fans by the pressure differential between the low pressure and high pressure sides of the blade. The winglet acts as a barrier, which substantially blocks leakage around the blade tip, thus suppressing vortices. Technical advantages include noise reduction, because there are no shedding vortices to create noise as the blades pass the struts; increased aerodynamic efficiency of the fan, providing higher air flow for the same fan speed, size, and power, because less energy is lost in vortices; and minimal cost impacts, because housings currently used for fans can still be used with standard finger guards and because winglets and blades can be formed integrally of injection molded plastic.
Claims17
A fan operable to generate a flow of air from a low pressure region to a high pressure region comprising:
- a base;
- a hub rotatably mounted to said base;
- a plurality of blades attached at proximal ends thereof to said hub and toward the distal ends thereof projecting in a substantially radial direction away from said hub;
- a stationary venturi attached to said base, said venturi having an inner surface rotationally symmetric about said hub;
- a winglet attached to said blade distal from said hub, said winglet extending generally in a plane perpendicular to said radial direction of said blade;
- and
- said winglet operable to substantially block a leakage flow of air around said distal end of said blade from said high pressure region to said low pressure region.
A method of enhanced fan performance, comprising:
- attaching a winglet to a blade of said fan adjacent the end of said blade radially distal from the hub thereof, said winglet forming a barrier extending generally in a plane perpendicular to said radial direction of said blade;
- rotating said blade about said hub, such that an air pressure gradient is induced across said blade in a direction substantially parallel to the axis of said rotation;
- substantially blocking with said winglet the leakage flow of air produced by said air pressure gradient;
- and
- substantially reducing shedding vortices created by said leakage flow of air.
Dependencies are inferred from the claim text.