| 摘要 |
PURPOSE:To reduce noises without the characteristics of a blower being affected, by forming the inlet section of each fan side guide vane 9 in a simple shape of substantially convex-round so that the turbulent flow of fluid is eliminated. CONSTITUTION:The inlet section of a fan side guide vane 9 is formed in such a simple shape that is provided with a substantially rounded part 16 which has a radius of curvature R within a range of 1/3H<=R<=2/3H, where H is the height of the fan side guide vane 9. When an impeller having 7 blades (Z=7), is rotated at a rotational speed N=23,000rpm, the peak level is lowered and as well an effect may be obtained concerning two or three harmonics by applying a countermeasure for noise. It is aimed that noises are reduced without any turbulent flow being brought about. |
