Airfoil, turbine blade including the airfoil, and gas turbine including the turbine blade

A turbine blade mounted on a turbine rotor disk and rotated by high-pressure combustion gas, the turbine blade comprising:

• a root portion coupled to the turbine rotor disk;
• and
• an airfoil coupled to the root portion, and having a cooling flow passage comprising a first cooling flow passage and a second cooling flow passage formed in the airfoil,
• wherein the airfoil comprises:
• a suction side having an outwardly convex surface;
• a pressure side having a concave surface toward the suction side;
• a leading edge connecting the suction side and the pressure side and defining a front end of the airfoil;
• a trailing edge connecting the suction side and the pressure side and defining a rear end of the airfoil;
• the cooling flow passage configured to guide cooling fluid introduced from a lower portion of the suction side and the pressure side, to one or more flow channels respectively at the suction side and the pressure side, and then discharge the cooling fluid to a region rearward of the trailing edge;
• a flow guide part provided in each of the one or more flow channels and forming a cooling space;
• and
• a plurality of cooling fluid spray holes formed in the flow guide part and configured to spray the cooling fluid supplied into the one or more flow channels to the suction side and the pressure side, each forming an inner surface of the cooling space,
• wherein a plurality of flow guides protruding toward the cooling space are provided on one surface of the flow guide part,
• a plurality of impingement holes, each in communication with a corresponding one of the plurality of cooling fluid spray holes, are formed respectively in the plurality of flow guides,
• a circumferential surface of each of the plurality of flow guides has a circular shape, and each of the plurality of cooling fluid spray holes is disposed at a center of a corresponding flow guide of the plurality of flow guides, and
• each of the plurality of flow guides protrudes obliquely from its circumferential surface toward a center where a corresponding impingement hole is formed.

A gas turbine comprising:

• a compressor configured to compress intake air;
• a combustor configured to mix compressed air from the compressor with fuel and burn the mixture;
• and
• a turbine configured to generate power using combustion gas from the combustor, and comprising turbine vanes configured to guide the combustion gas on a combustion gas path along which the combustion gas flows and turbine blades that are rotated by the combustion gas on the combustion gas path,
• wherein the turbine blade comprises an airfoil having a cooling flow passage comprising a first cooling flow passage and a second cooling flow passage formed in the airfoil,
• wherein the airfoil comprises:
• a suction side having an outwardly convex surface;
• a pressure side having a concave surface toward the suction side;
• a leading edge connecting the suction side and the pressure side and defining a front end of the airfoil;
• a trailing edge connecting the suction side and the pressure side and defining a rear end of the airfoil;
• the cooling flow passage configured to guide cooling fluid introduced from a lower portion of the suction side and the pressure side, to one or more flow channels respectively at the suction side and the pressure side, and to discharge the cooling fluid to a region rearward of the trailing edge;
• a flow guide part provided in each of the one or more flow channels and forming a cooling space;
• and
• a plurality of cooling fluid spray holes formed in the flow guide part and configured to spray the cooling fluid supplied into the one or more flow channels to the suction side and the pressure side, each forming an inner surface of the cooling space,
• wherein a plurality of flow guides protruding toward the cooling space are pr vided on one surface of the flow guide part,
• a plurality of impingement holes, each in communication with a corresponding one of the plurality of cooling fluid spray boles, are formed respectively in the plurality of flow guides,
• a circumferential surface of each of the plurality of flow guides has a circular shape, and each of the plurality of cooling fluid spray holes is disposed at a center of a corresponding flow guide of the plurality of flow guides, and
• each of the plurality of flow guides protrudes obliquely from its circumferential surface toward a center where a corresponding impingement hole is formed.