Turbine blade, turbine, and method for cooling turbine blade
A turbine blade includes a blade main body that includes a cooling flow path formed inside, through which a cooling medium flows; and a plurality of turbulators that are aligned in a flow direction of the cooling medium, project into the cooling flow path from an inner surface of the blade main body, and extend in a direction intersecting with the flow direction. At least one of the turbulators is a first turbulator. The first turbulator includes a first portion and a second portion. The first portion is connected to the first portion and has a projecting height from the inner surface that changes at a first change ratio along a direction intersecting with the flow direction. The second portion has a projecting height from the inner surface that changes at a second change ratio higher than the first change ratio along the direction intersecting with the flow direction.
1. A turbine blade comprising:
a blade main body that includes a cooling flow path formed inside, through which a cooling medium flows;
a platform that defines a gas path face, the gas path face being a radial face of a gas path; and
a plurality of turbulators that are aligned in a flow direction of the cooling medium, project into the cooling flow path from an inner surface of the blade main body, and extend in a direction intersecting with the flow direction, wherein
at least one of the turbulators is a first turbulator,
the first turbulator includes a first portion and a second portion, the first portion having a projecting height from the inner surface that changes at a first change ratio along a direction intersecting with the flow direction, the second portion having a connection point at which one end of the second portion is connected to the first portion and having a projecting height from the inner surface that changes at a second change ratio higher than the first change ratio along the direction intersecting with the flow direction,
the first change ratio of the first portion is 0 or has a value indicating that the projection height decreases as being closer to the second portion, and
at least a portion of the second portion of the first turbulator is located radially inward of the gas path face when seen from the direction intersecting with the flow direction, and at least a portion of the first portion of the first turbulator is located radially outward of the gas path face when seen from the direction intersecting with the flow direction.
2. The turbine blade according to claim 1 , wherein the projecting height of the second portion decreases as being farther from the first portion.
3. The turbine blade according to claim 1 , wherein an edge of the second portion on a side opposite to the inner surface forms a circular arc shape being tangent to the inner surface when seen from the flow direction.
4. The turbine blade according to claim 1 , wherein the first portion and the second portion of the first turbulator are connected to each other in a curved form.
5. The turbine blade according to claim 1 , wherein the first turbulator is the turbulator located at a position closest to one side in the flow direction among the turbulators.
6. The turbine blade according to claim 1 , wherein second turbulators other than the first turbulator among the turbulators each have a constant projecting height from the inner surface along the direction intersecting with the flow direction.
7. The turbine blade according to claim 6 , wherein edges of the first turbulator and each of the second turbulators on the inner surface side are parallel to each other and edges of the first turbulator and each of the second turbulators on a side farther from the inner surface are not parallel to each other.
8. The turbine blade according to claim 1 , wherein
the blade main body includes a plurality of partition walls dividing the cooling flow path into a plurality of cavities,
the plurality of turbulators includes second turbulators other than the first turbulator, and
wherein for each second turbulator, opposite ends of the second turbulator are respectively connected
to adjacent ones of the partition walls, or
to the inner surface of the blade main body on a leading edge side and to an adjacent one of the partition walls, or
to the inner surface on a trailing edge side and to an adjacent one of the partition walls.
9. The turbine blade according to claim 1 , wherein
the blade main body includes a plurality of partition walls dividing the cooling flow path into a plurality of cavities,
the partition walls include a first partition wall close to the first portion and a second partition wall close to the second portion, and
a distance between the second partition wall and the second portion is larger than half of a distance between the first partition wall and the connection point.
10. The turbine blade according to claim 1 , wherein
the cooling flow path is a first cooling flow path,
the blade main body has a second cooling flow path which includes turbulators projecting into the second cooling flow path, the turbulators of the second cooling flow path including no first turbulator, and
at least a portion of the turbulators in the second cooling flow path is located at a position on the inner side in the radial direction relative to the gas path face which is a radial face of a gas path.
11. A turbine comprising:
a rotor main body that rotates about an axial line; and
the turbine blade according to claim 1 that is provided on the rotor main body.
12. A method for cooling a turbine blade,
the turbine blade including:
a blade main body that includes a cooling flow path formed inside, through which a cooling medium flows;
a platform that defines a gas path face, the gas path face being a radial face of a gas path; and
a plurality of turbulators that are aligned in a flow direction of the cooling medium, project into the cooling flow path from an inner surface of the blade main body, and extend in a direction intersecting with the flow direction,
at least one of the turbulators being a first turbulator,
the first turbulator including a first portion and a second portion, the first portion having a projecting height from the inner surface that changes at a first change ratio along a direction intersecting with the flow direction, the second portion having a connection point at which one end of the second portion is connected to the first portion and having a projecting height from the inner side that changes at a second change ratio higher than the first change ratio along the direction intersecting with the flow direction,
the first change ratio of the first portion being 0 or having a value indicating that the projection height decreases as being closer to the second portion, and
at least a portion of the second portion of the first turbulator being located radially inward of the gas path face when seen from the direction intersecting with the flow direction, and at least a portion of the first portion of the first turbulator being located radially outward of the gas path face when seen from the direction intersecting with the flow direction,
the method comprising:
cooling the blade main body by causing cooling air to flow through the cooling flow path; and
performing heat exchange between the blade main body and the cooling air while changing a flow direction of the cooling air by the first turbulator and second turbulators other than the first turbulator, to cool the turbine blade.