Gas Turbine Airfoil Cooling Discharge Relocation
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Solution Overview
Problem
In gas turbine engines, pressure side biased cooling discharge openings at the trailing edge of bowed airfoils are difficult and expensive to manufacture due to metal flash issues and limited access, leading to compromised mechanical strength and increased scrap rates.
Innovation Solution
Employing only center cooling discharge openings in the fillet of bowed airfoils, which eliminates metal flash and allows for greater mechanical strength and improved heat transfer, reducing the need for manual removal and associated costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If pressure side biased cooling discharge openings are used at the trailing edge of bowed airfoils, then sufficient cooling air area is provided for thin trailing edges, but metal flash issues and limited access make manufacturing difficult and expensive
Solution Approach 1:
The patent extracts the cooling discharge openings from the pressure side biased position and relocates them to the suction side of the airfoil. This extraction eliminates the metal flash issues and manufacturing difficulties associated with pressure side biased openings while maintaining sufficient cooling air area for thin trailing edges.
Solution Approach 2:
Instead of biasing cooling discharge openings toward the pressure side, the patent inverts the approach by positioning them on the suction side. This inversion resolves the manufacturing problems while still providing adequate cooling area through the thin trailing edge.
2Temperature
If pressure side biased cooling discharge openings are used, then cooling area is increased, but mechanical strength is compromised and scrap rates increase
Solution Approach 1:
The patent extracts the cooling discharge openings from the pressure side location that compromises mechanical strength and relocates them to the suction side. This maintains the necessary cooling air area while preserving the structural integrity of the airfoil.
3Manufacturing precision
If manual removal of metal flash is performed, then manufacturing precision is improved, but productivity decreases and costs increase
Solution Approach 1:
The patent extracts the problematic pressure side biased cooling discharge openings and relocates them to the suction side, eliminating the need for manual metal flash removal. This improves productivity while maintaining manufacturing precision through the redesigned opening location.
Solution Approach 2:
The suction side positioning of cooling discharge openings allows the casting process to self-complete without requiring subsequent manual intervention for metal flash removal, thereby improving productivity while maintaining precision.
4Loss of energy
If bowed airfoils are used to reduce vortices, then turbine efficiency is improved, but manufacturing complexity increases
Solution Approach 1:
The patent extracts the cooling discharge openings from the complex pressure side biased position on bowed airfoils and relocates them to the simpler suction side position. This maintains the vortex-reducing benefits of bowed airfoils while reducing manufacturing complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution enhances mechanical strength, reduces structural variations, and extends the life of turbine components by improving internal heat transfer and minimizing temperature increases in critical areas.
Implementation Method 1
A portion of the cooling air passes through and cools the airfoil before discharging through cooling discharge openings at a trailing edge of the airfoil
Implementation Method 2
The cooling air discharging from these openings cools the trailing edge
Implementation Method 3
Turbine engines may include rotor or vane airfoils that are curved or bowed to improve the efficiency of the turbine engine by directing the combustion gases away from platforms at the ends of the airfoils, thereby reducing the vortices
Data Source
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AI summary
An assembly for a gas turbine engine includes a first platform and an airfoil extending from the first platform. The airfoil includes a first fillet, pressure side biased discharge openings, and a first center cooling discharge opening. A pressure side wall of the airfoil and the first platform form an acute angle at the trailing edge. The first fillet is formed around a perimeter of the airfoil where the airfoil extends from the first platform. The pressure side biased cooling discharge openings are along the trailing edge outside of the first fillet. Each pressure side biased cooling discharge opening extends from the trailing edge along the pressure side wall. The first center cooling discharge opening extends along the trailing edge into the first fillet and is centrally located between the pressure side wall and the suction side wall.