| 摘要 |
An air moving device such as an axial cooling fan comprises a rotatable shaft assembly and a plurality of fan blades coupled to the rotatable shaft assembly, each of the fan blades having a trailing edge when the rotatable shaft assembly is rotated in a given direction. In accordance with one illustrative embodiment of the invention, at least one of the fan blades has a sound reducing material attached thereto alongside the trailing edge thereof. The sound reducing material reduces aeroacoustic noise by reducing the aerodynamic effect that occurs when turbulence produced by the pressure differential between the two sides of one blade comes into contact either with the trailing edge of the given blade which created it, or, more significantly, with the following blade, at or near that blade's trailing edge. In various embodiments the sound reducing material may comprise felt, loops from a hook-and-loop-type fastener such as that sold under the "Velcro" trademark, or a small piece of fiberglass, cotton or wool batting. In one illustrative embodiment, the sound reducing material is advantageously attached to the fan blade on the high pressure side thereof. |
