Three-dimensional axial-flow turbine stage

An axial-flow turbine stage comprising:

• a plurality of moving blades fixedly mounted on a rotor shaft in a circumferential arrangement about an axis of the rotor shaft;
• and
• a plurality of stationary blades disposed axially opposite to the moving blades in a circumferential arrangement about the axis of the rotor shaft;
• wherein each of the plurality of stationary blades has a trailing edge convex toward a face side with respect to a radial line radially extending from the axis of the rotor shaft,
• a blade center-of-gravity line of each of the plurality of moving blades is convex toward the face side with respect to a radial line radially extending from the axis of the rotor shaft, and
• shapes of the stationary blades and the moving blades meet conditions expressed by:
• 1<θnr/θbr<3
• where, as viewed from a direction of the axis of the rotor shaft:
• θnt is an angle between a tangent to a trailing edge of the stationary blade at a tip of the stationary blade and a radial line passing the tip of the stationary blade and radially extending from the axis of the rotor shaft;
• θnr is an angle between a tangent to the trailing edge of the stationary blade at a root of the stationary blade and a radial line passing the root of the stationary blade and radially extending from the axis of the rotor shaft;
• θbt is an angle between a tangent to the blade center-of-gravity line of the moving blade at a tip of the moving blade and a radial line passing the tip of the moving blade and radially extending from the axis of the rotor shaft;
• and
• θbr is an angle between a tangent to the blade center-of-gravity line of the moving blade at the root of the moving blade and a radial line passing the root of the moving blade and radially extending from the axis of the rotor shaft.

An axial-flow turbine stage comprising:

• a plurality of moving blades fixedly mounted on a rotor shaft in a circumferential arrangement about an axis of the rotor shaft;
• and
• a plurality of stationary blades disposed axially opposite to the moving blades in a circumferential arrangement about the axis of the rotor shaft;
• wherein each of the plurality of stationary blades has a trailing edge convex toward a face side with respect to a radial line radially extending from the axis of the rotor shaft,
• a blade center-of-gravity line of each of the plurality of moving blades is convex toward the face side with respect to a radial line radially extending from the axis of the rotor shaft, and
• shapes of the stationary blades and the moving blades meet conditions expressed by:
• 0.3<θnt/θbt<1
• where, as viewed from a direction of the axis of the rotor shaft:
• θnt is an angle between a tangent to a trailing edge of the stationary blade at a tip of the stationary blade and a radial line passing the tip of the stationary blade and radially extending from the axis of the rotor shaft;
• θnr is an angle between a tangent to the trailing edge of the stationary blade at a root of the stationary blade and a radial line passing the root of the stationary blade and radially extending from the axis of the rotor shaft;
• θbt is an angle between a tangent to the blade center-of-gravity line of the moving blade at a tip of the moving blade and a radial line passing the tip of the moving blade and radially extending from the axis of the rotor shaft;
• and
• θbr is an angle between a tangent to the blade center-of-gravity line of the moving blade at the root of the moving blade and a radial line passing the root of the moving blade and radially extending from the axis of the rotor shaft.

An axial-flow turbine stage comprising:

• a plurality of moving blades fixedly mounted on a rotor shaft in a circumferential arrangement about an axis of the rotor shaft;
• and
• a plurality of stationary blades disposed axially opposite to the moving blades in a circumferential arrangement about the axis of the rotor shaft;
• wherein each of the plurality of stationary blades has a trailing edge convex toward a face side with respect to a radial line radially extending from the axis of the rotor shaft,
• a blade center-of-gravity line of each of the plurality of moving blades is convex toward the face side with respect to a radial line radially extending from the axis of the rotor shaft, and
• shapes of the stationary blades and the moving blades meet conditions expressed by:
• 1<θnr/θbr<3 0.3<θnt/θbt<1
• where, as viewed from a direction of the axis of the rotor shaft:
• θnt is an angle between a tangent to a trailing edge of the stationary blade at a tip of the stationary blade and a radial line passing the tip of the stationary blade and radially extending from the axis of the rotor shaft;
• θnr is an angle between a tangent to the trailing edge of the stationary blade at a root of the stationary blade and a radial line passing the root of the stationary blade and radially extending from the axis of the rotor shaft;
• θbt is an angle between a tangent to the blade center-of-gravity line of the moving blade at a tip of the moving blade and a radial line passing the tip of the moving blade and radially extending from the axis of the rotor shaft;
• and
• θbr is an angle between a tangent to the blade center-of-gravity line of the moving blade at the root of the moving blade and a radial line passing the root of the moving blade and radially extending from the axis of the rotor shaft.