摘要 |
A plurality of vaned diffusers is disposed on a concentric plate at intervals in a circumferential direction thereof, and each of the diffusers is a curvilinear element three-dimensional diffuser having blades which are extended from a hub side of a impeller to a shroud side thereof. The blades are formed in a form in which a blade serving as a reference is stacked in a direction of the height of the blade, which is a direction of a gap between the hub and the shroud. A dihedral distribution in which moving in a direction perpendicular to a chord direction linking a leading edge of the blade as the reference with a tailing edge thereof, is set as a positive movement is non-uniform from an end portion on the hub side to an intermediate portion of the height of the blade. |