Abstract: Briefly, embodiments of a fan for moving a volume of compressible fluid from an upstream side to a downstream side may comprise a vortex circulation channel formed within a shroud substantially surrounding the blades of the fan. As a portion of one or more blades of the fan moves within the vortex circulation channel, a vortex that is formed and confined within the channel may reduce formation of a vortex within the fan working area, thereby bringing about an increase in a volume of the compressible fluid capable of being moved by the fan. In an embodiment, a fin or other protrusion disposed on a tip portion of a blade may additionally increase flow of a compressible fluid through a fan. In an embodiment, use of a wraparound leading edge of a fan shroud may bring about further increases in volume of compressible fluid flow.

Abstract: Briefly, embodiments of a fan for moving a volume of compressible fluid from an upstream side to a downstream side may comprise a vortex circulation channel formed within a shroud substantially surrounding the blades of the fan. As a portion of one or more blades of the fan moves within the vortex circulation channel, a vortex that is formed and confined within the channel may reduce formation of a vortex within the fan working area, thereby bringing about an increase in a volume of the compressible fluid capable of being moved by the fan. In an embodiment, a fin or other protrusion disposed on a tip portion of a blade may additionally increase flow of a compressible fluid through a fan. In an embodiment, use of a wraparound leading edge of a fan shroud may bring about further increases in volume of compressible fluid flow.