Abstract: A turbine blade includes: a pin fin passage formed inside a trailing edge portion of an airfoil part, extending toward a trailing edge of the airfoil part, and opening to outside of the airfoil part at the trailing edge; and a plurality of pin fins connecting a pair of facing inner walls constituting the pin fin passage. The pin fin passage includes a first region and a second region on the trailing edge side of the first region. The plurality of pin fins includes a plurality of first pin fins disposed in the first region and a plurality of second pin fins disposed in the second region. A first diameter of the first pin fins is larger than a second diameter of the second pin fins. A first pin pitch of the first pin fins is larger than a second pin pitch of the second pin fins.

Abstract: A ring-segment surface-side member is included in a ring segment disposed at a position opposite to a turbine blade on a stationary side of a gas turbine, serves as a part of a combustion gas flow path through which combustion gas flows, and is formed of a ceramic matrix composite. The ring-segment surface-side member includes: a surface portion forming the combustion gas flow path; a turned-back portion including a first part extending outward in a radial direction of the gas turbine from the surface portion and a second part extending toward a central line of the surface portion from an end part of the first part; and a protrusion portion extending outward from the turned-back portion in the radial direction of the gas turbine.

Abstract: A ring-segment surface-side member is included in a ring segment disposed at a position opposite to a turbine blade on a stationary side of a gas turbine, serves as a part of a combustion gas flow path through which combustion gas flows, and is formed of a ceramic matrix composite. The ring-segment surface-side member includes: a surface portion forming the combustion gas flow path; a turned-back portion including a first part extending outward in a radial direction of the gas turbine from the surface portion and a second part extending toward a central line of the surface portion from an end part of the first part; and a protrusion portion extending outward from the turned-back portion in the radial direction of the gas turbine.