Turbine Blade Trailing Edge Cooling Feed Curvature
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Solution Overview
Problem
Existing turbine blade cooling passageway designs often suffer from flow separation and reduced cooling efficiency due to abrupt turns in the trailing edge cavity, leading to recirculation and reduced flow rates.
Innovation Solution
The implementation of a dog leg turn in the trunk section at the entrance to the trailing edge cavity, which shifts the flow to avoid separation by creating a less abrupt turning angle and promotes a more axial flow direction, reducing the diffusion angle to prevent separation zones and enhance cooling efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional trailing edge cavity design with abrupt turns is used, then the structural simplicity is maintained, but flow separation occurs and cooling efficiency is reduced
Solution Approach 1:
The patent applies curvature by replacing abrupt angular turns with curved passageway sections in the trailing edge cavity. The curved geometry allows cooling air to transition smoothly through the cavity, eliminating flow separation zones that occur with sharp turns. This curved design maintains structural simplicity while significantly improving cooling efficiency by ensuring continuous, attached flow throughout the passageway.
2Productivity
If abrupt turns are used in the trailing edge cavity, then the manufacturing process is simplified, but recirculation zones form and reduce flow rates
Solution Approach 1:
The curved passageway design replaces abrupt turns with smooth transitions that prevent recirculation zone formation. The curvature ensures that cooling air maintains attached flow throughout the trailing edge cavity, maximizing flow rate to the trailing edge cooling slots. While the curved geometry requires more complex tooling, modern casting and additive manufacturing processes can produce these curved paths without significantly increasing manufacturing complexity.
3Reliability
If a straight passageway configuration is used, then the design is simple, but flow separation occurs at the trailing edge cavity entrance
Solution Approach 1:
The patent introduces curved transition sections at the trailing edge cavity entrance and throughout the passageway. These curved sections guide the cooling air smoothly from the root into the trailing edge cavity, preventing flow separation that would occur with straight or abrupt configurations. The curved geometry stabilizes the flow by maintaining attached boundaries throughout the passageway, ensuring reliable cooling performance.
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 design reduces flow separation and enhances cooling efficiency by ensuring a smoother flow transition into the trailing edge cooling slot, effectively addressing the issues of recirculation and reduced flow rates in prior art designs.
Implementation Method 1
Existing turbine blade cooling passageway designs often suffer from flow separation and reduced cooling efficiency due to abrupt turns in the trailing edge cavity
Implementation Method 2
leading to recirculation and reduced flow rates
Data Source
Figure 1
Figure 2
Figure 2A
AI summary
A turbine blade has an attachment root and an airfoil. A cooling passageway system has a plurality of trunks extending from respective inlets along the root inner diameter end from a leading trunk near a first axial end to a trailing trunk near a second axial end; and a plurality of outlets along the airfoil including trailing edge outlets fed by the trailing trunk. Viewed normal to a root end-to-end centerplane: the trailing trunk has a turn passing forward and then rearward; an outside of the turn protrudes forward; and the outside of the turn has a tighter curvature than an inside of the turn.