Abstract: A propulsion device includes: a duct in which a flow path extending in a direction of an axis; a fan which is provided with a) an outer peripheral ring formed in an annular shape surrounding the axis and installed to be relatively rotatable around the axis with respect to the duct, b) a plurality of fan blades arranged at intervals in a circumferential direction such that each blade is extended from the outer peripheral ring toward the inside of the flow path, and c) an inner peripheral ring formed in an annular shape being connected radially inner end portions of the plurality of fan blades and in which an air flow passage is formed so that air flows therethrough in the direction of the axis; and a motor which drives the fan to rotate around the axis.

Abstract: A propulsion device includes: a duct in which a flow path extending in a direction of an axis; a fan which is provided with a) an outer peripheral ring formed in an annular shape surrounding the axis and installed to be relatively rotatable around the axis with respect to the duct, b) a plurality of fan blades arranged at intervals in a circumferential direction such that each blade is extended from the outer peripheral ring toward the inside of the flow path, and c) an inner peripheral ring formed in an annular shape being connected radially inner end portions of the plurality of fan blades and in which an air flow passage is formed so that air flows therethrough in the direction of the axis; and a motor which drives the fan to rotate around the axis.

Abstract: Sectional profiles close to a tip 124 and a part between a midportion 125 and a hub 123 are shifted to the upstream of an operating fluid flow in a sweep direction. Accordingly, an S shape is formed in which the tip 124 and the part between the midportion 125 and the hub 123 protrude. As a result, it is possible reduce various losses due to shook, waves, thereby forming a transonic airfoil having an excellent aerodynamic characteristic.

Abstract: An axial-flow fluid machine blade which achieves reduction of the frictional loss of the blade and provision of a high surge-resistant property is provided. An axial-flow fluid machine blade 60 used for an axial-flow fluid machine includes a leading edge 61 projecting at the tip portion and the root portion thereof toward the upstream side and a trailing edge 62 projecting at the tip portion, the mid-span portion and the root portion thereof toward the downstream side.

Abstract: Sectional profiles close to a tip 124 and a part between a midportion 125 and a hub 123 are shifted to the upstream of an operating fluid flow in a sweep direction. Accordingly, an S shape is formed in which the tip 124 and the part between the midportion 125 and the hub 123 protrude. As a result, it is possible reduce various losses due to shook, waves, thereby forming a transonic airfoil having an excellent aerodynamic characteristic.

Abstract: An axial-flow fluid machine blade which achieves reduction of the frictional loss of the blade and provision of a high surge-resistant property is provided. An axial-flow fluid machine blade 60 used for an axial-flow fluid machine includes a leading edge 61 projecting at the tip portion and the root portion thereof toward the upstream side and a trailing edge 62 projecting at the tip portion, the mid-span portion and the root portion thereof toward the downstream side.