| 摘要 |
In order to prevent a reduction in speed in the vicinity of a bell mouth and prevent non-uniform speed at the outlet of a blade and the outlet of the bell mouth when a forward-swept blade that reduces the blade-tip vortex is utilized as a noise reduction means, with the blades of this propeller fan, the rear edge part, when rotationally projected on a plane passing through the rotational axis, is formed so as to bend with a first curvature from the rotational axis toward the blade tip part and from the suction side to the discharge side, and is formed so as to bend at an inflection point with a second curvature which is less than the first curvature. |
