Turbine Blade Tip Cooling via Segmented Passageways
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Solution Overview
Problem
Turbine engine blades, particularly in the high-pressure turbine section, face thermal fatigue issues in the tip region due to inadequate cooling, where existing cooling methods do not effectively manage heat distribution and airflow to prevent overheating.
Innovation Solution
A novel casting core design for gas turbine engine blades that includes a network of passageways and outlets strategically positioned to minimize heating of cooling air before it reaches critical areas, using a 'fir tree' attachment root and a tip flag passageway system to efficiently distribute cooling air and reduce thermal stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cooling air is passed through convoluted paths through the airfoil, then cooling coverage is improved, but heating of cooling air increases and airflow efficiency decreases
Solution Approach 1:
The cooling system is divided into multiple independent passageways: a first cooling passageway for the platform region and a second cooling passageway for the airfoil region. This segmentation allows cooling air to be delivered directly to different regions without traversing convoluted paths, reducing heating while maintaining comprehensive cooling coverage.
Solution Approach 2:
A platform cooling passageway acts as an intermediary system that receives cooling air and distributes it to both the platform region and the airfoil region through separate outlets. This intermediary structure enables efficient heat transfer to targeted regions without requiring the cooling air to travel through long, heated paths.
2Reliability
If additional cooling passageways are added to cool the tip region, then thermal fatigue resistance is improved, but device complexity increases
Solution Approach 1:
The platform cooling passageway and airfoil cooling passageway are merged into a single integrated cooling system that serves both regions. This consolidation provides enhanced cooling coverage for thermal fatigue resistance while avoiding the complexity of completely separate cooling systems, as both passageways can be formed together during blade manufacturing.
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
The solution effectively reduces thermal fatigue by optimizing the routing of cooling air to align with low-temperature regions, maintaining airflow efficiency and preserving the external profile of the blade, thus enhancing the cooling performance and longevity of the turbine engine blades.
Implementation Method 1
The cooling air is passed through convoluted paths through the airfoil, with at least a portion exiting the blade through apertures in the airfoil
Data Source
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AI summary
A turbine engine blade (20) has an attachment root (42), a platform (40) outboard of the attachment root (42), and an airfoil (22) extending from the platform (40). The airfoil (22) has pressure and suction sides (34, 36) extending between leading and trailing edges (30, 32). An internal cooling passageway network includes at least one inlet (44) in the root (42) and a plurality of outlets (334, 376) along the airfoil. The passageway network includes a leading spanwise cavity (310) fed by a first trunk (323). A streamwise cavity (324) is inboard of a tip (26) of the airfoil. A spanwise feed cavity (326) feeds the streamwise cavity (324) absent down-pass. A second trunk (327) feeds the spanwise feed cavity (326).