| 摘要 |
Provided is a multi-blade fan in which the prominence of wind noise, low-frequency broadband noise, and specific discrete-frequency noise is minimized, and in which a noise-reduction property is enhanced. In a cross-flow fan (10), a plurality of blades (101-135) are secured to a support plate (50) that rotates about a rotary shaft. The plurality of blades (101-135) are secured to the support plate (50) such that inter-blade pitch angles Pt1-Pt35 relative to the rotary shaft assumes a prescribed arrangement. The plurality of blades (101-135) are disposed such that, with respect to the amplitude values of periodic functions at individual orders when the prescribed arrangement is expanded in a periodic Fourier series, the maximum amplitude value is less than 200% of the second-largest amplitude value. |
