| 主权项 |
1. A turbine rotor blade for a turbine section of an engine, comprising:
a platform; and an airfoil extending from the platform into a mainstream gas path of the turbine section, the airfoil comprising
a pressure side wall,a suction side wall joined to the pressure side wall at a leading edge and a trailing edge, anda tip cap extending between the suction side wall and the pressure side wall,an internal cooling circuit having a tip cap passage configured to deliver cooling air to the tip cap, the airfoil including an interior wall that defines the tip cap passage with the tip cap, the pressure side wall, and the suction side wall, wherein the tip cap passage has a chordwise length between an inlet and an outlet at the trailing edge; anda flow accelerator positioned within the tip cap passage of the internal cooling circuit, the flow accelerator extending in a radial direction from the tip cap toward the interior wall to define at least a first flow area for the cooling air between the flow accelerator and the pressure side wall and a second flow area for the cooling air between the flow accelerator and the suction side wall,wherein the tip cap passage has at least a first cross-sectional area defined between the tip cap, the internal wall, the suction side wall, and the pressure side wall, and wherein the flow accelerator, at a position corresponding to the first cross-sectional area, has a second cross-sectional area that is at least 50% of the first cross-sectional area, andwherein the flow accelerator is generally tear-drop or airfoil shaped and generally extends in a chordwise direction to accelerate a flow of the cooling air through the tip cap passage,wherein the flow accelerator is hollow with an outer wall and interior space, and wherein the internal cooling circuit includes a central passage that delivers cooling air that impinges on an underside of the outer wall within the interior space. |
