| 摘要 |
PROBLEM TO BE SOLVED: To provide a fluid machine capable of achieving noise reduction by maintaining long a release suppression effect by longitudinal vortices on a blade negative pressure surface.SOLUTION: A blade front edge portion 183 of a blade 18 includes a plurality of protrusions 185 aligned along the blade front edge portion 183, so that a plurality of paired longitudinal vortices can be generated in an air flow along a negative pressure surface of the blade 18. The negative pressure surface of the blade 18 has a surface shape for reducing the viscosity resistance of the air against the negative pressure surface, so that energy dissipation from the longitudinal vortices due to the friction between the longitudinal vortices and the negative pressure surface can be reduced. Owing to this, the longitudinal vortices are maintained for long time up to a downstream side along the negative pressure surface of the blade 18. It is, therefore, possible to maintain long the effect of suppressing the release of the air flow from the negative pressure surface by the longitudinal vortices up to the downstream side in the air flow on the negative pressure surface of the blade 18.SELECTED DRAWING: Figure 2 |
