Abstract: An object is to improve the efficiency of a compressor by preventing localized concentration of a boundary layer occurring on the surface of a hub, and by inducing a reduction in the thickness of the boundary layer. There is a compressor impeller having a plurality of blades, and a hub disposed at the root of this plurality of blades, and in which at least part of the surface of the hub on which a fluid flows is inclined in relation to an axis of rotation, wherein a boundary layer reduction part which induces a reduction in the thickness of a boundary layer occurring due to a flow of fluid is provided on the surface of the hub.

Abstract: In a centrifugal compressing apparatus, a height of a blade of an impeller is made to decrease gradually from a front edge thereof to a rear edge thereof, and a rate of change of the height of the blade is relatively large near the rear edge. The height of the blade can be made large at the rear edge side under the design restriction that an exit width of the rear edge of the blade is set to a predetermined design value. The ratio of the width of the clearance and the height of the blade is thereby made relatively large. As a result, the ratio of a flow path area occupied by a clearance flow to a flow path area occupied by a main flow is reduced and since pressure loss is thus made small, drop in the efficiency can be prevented.

Abstract: A trailing edge of a turbine rotor blade is formed so that a deflection angle of a blade surface in a downstream side of a maximum blade thickness portion is a predetermined value or less, by forming the trailing edge of the rotor blade so as to be inclined from a center line of a blade thickness toward an extension line of a suction surface. Since the trailing edge of the rotor blade is thus formed, a rapid increase of the deflection angle is prevented in a trailing edge portion of the rotor blade. Accordingly, a rapid ascent portion and a rapid deceleration portion are not generated in a suction surface velocity in a main stream unlike the conventional case.

Abstract: On a suction surface side of a blade in an impeller, a convex portion is formed to assume a curved line from a front edge portion to a throat portion substantially in the middle in a radial direction, and this convex portion is formed to be flat assuming a curved line from the throat portion toward a rear edge portion, whereby this convex portion is formed in a position where a relative inlet velocity of fluid into the impeller is Mach number Ma?1.

Abstract: An object is to provide an impeller which can suppress or prevent reversed flow of a fluid within a diffuser and raise the efficiency of a mixed flow compressor. In an impeller of a mixed flow compressor that has a plurality of blades, and a hub disposed at the root of this plurality of blades, and in which the surface of the hub on which trailing edges of the plurality of blades are located, is inclined with respect to a rotation axis in a plane that includes the rotation axis, the trailing edges of the plurality of blades are formed so that they are positioned on a line approximately parallel to an axis of rotation of the hub.

Abstract: At least the throat of the suction surface of a conventionally-used diffuser blade having a two-dimensional shape is cut into a concave shape with a ball end mill. In the throat, the nearer to the bottom of the concave shape, the higher the gas pressure becomes, and therefore the gas flows from the concave bottom toward the hub end and the shroud end thereby to reduce the thickness of the boundary layer formed on the hub end and the shroud end.

Abstract: A mixed flow turbine includes a hub attached to a rotation axis and a plurality of rotor blades. Each of the plurality of rotor blades is attached to the hub in a radial direction, and the hub is rotated based on fluid supplied to a rotation region of the plurality of rotor blades. Each of the plurality of rotor blades has a curved shape that convexly swells on a supply side of the fluid.

Abstract: A mixed flow turbine includes a hub attached to a rotation axis and a plurality of rotor blades. Each of the plurality of rotor blades is attached to the hub in a radial direction, and the hub is rotated based on fluid supplied to a rotation region of the plurality of rotor blades. Each of the plurality of rotor blades has a curved shape that convexly swells on a supply side of the fluid.

Abstract: A trailing edge of a turbine rotor blade is formed so that a deflection angle of a blade surface in a downstream side of a maximum blade thickness portion is a predetermined value or less, by forming the trailing edge of the rotor blade so as to be inclined from a center line of a blade thickness toward an extension line of a suction surface. Since the trailing edge of the rotor blade is thus formed, a rapid increase of the deflection angle is prevented in a trailing edge portion of the rotor blade. Accordingly, a rapid ascent portion and a rapid deceleration portion are not generated in a suction surface velocity in a main stream unlike the conventional case.