Turbine Blade Cooling via Partial Tip Flag and Serpentine Channels
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Solution Overview
Problem
Current gas turbine engine airfoils face limitations in withstanding high temperature gas flows due to material properties and cooling capabilities, leading to reduced efficiency and shorter component life, particularly in high-pressure compressor sections where thermal loads are higher.
Innovation Solution
The design incorporates a configuration of cooling channels and core ties within airfoils, such as rotor blades and vanes, with serpentine channels, tip flags, and trailing edge channels, along with strategically positioned cooling holes and outflow orifices to manage cooling air pressure and flow effectively, enhancing thermal protection and manufacturability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If higher temperature gas flow is passed through the turbine to increase efficiency, then engine efficiency is improved, but the turbine inlet temperature is limited by the vane and blade material properties and cooling capabilities
Solution Approach 1:
The airfoil is divided into multiple functional zones with distinct cooling channel configurations: leading edge region with first cooling holes, mid-section with second cooling holes, and trailing edge with third cooling holes. Each region has tailored cooling characteristics to handle different thermal loads, allowing the blade to withstand higher overall temperatures while maintaining material property limits at critical locations.
Solution Approach 2:
Different regions of the airfoil are provided with different cooling hole patterns, channel configurations, and thermal protection characteristics. The leading edge receives intensive cooling due to highest thermal exposure, while other regions have proportionally reduced cooling provisions, optimizing the balance between thermal protection and gas flow temperature.
2Reliability
If cooling channels are added to protect airfoils from high temperature, then thermal protection is improved, but the device complexity increases
Solution Approach 1:
Multiple cooling functions are merged into a unified cooling channel system that distributes cooling air through serpentine channels to different regions of the airfoil. The cooling channels are integrated into the airfoil structure itself rather than being separate components, reducing overall system complexity while maintaining comprehensive thermal protection.
Solution Approach 2:
The cooling channels are configured to extend in multiple spatial dimensions within the airfoil structure, including axial, radial, and circumferential directions. This three-dimensional channel network provides comprehensive cooling coverage without requiring separate cooling systems for each region, simplifying the overall design.
3Productivity
If cooling holes are strategically positioned to manage cooling air pressure and flow, then cooling efficiency is improved, but the manufacturing precision requirements increase
Solution Approach 1:
The cooling holes are pre-positioned and pre-configured during the airfoil manufacturing process with precise locations optimized for cooling efficiency. The hole patterns, diameters, and orientations are predetermined based on thermal analysis, allowing the cooling system to function optimally without requiring complex post-manufacturing adjustments or high-precision field assembly.
4Reliability
If serpentine channels and core ties are incorporated to enhance cooling, then thermal protection is improved, but the manufacturing difficulty increases
Solution Approach 1:
The serpentine cooling channels are nested within the airfoil structure, with channels routed through the thickness of the airfoil body. Core ties are nested within the channel system to provide structural support while maintaining flow passages. This nested configuration provides comprehensive cooling and structural reinforcement without requiring external attachments or complex assembly operations.
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 configuration enhances cooling efficiency and thermal protection for airfoils, maintaining effective operation under high thermal loads and improving the endurance life of components while addressing manufacturing challenges.
Implementation Method 1
cooling air pressure and flow effectively, enhancing thermal protection
Implementation Method 2
serpentine channels, tip flags, and trailing edge channels, along with strategically positioned cooling holes
Data Source
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AI summary
A rotor blade (50) of a turbine engine may have internal passages to permit the travel of cooling air through the blade. These passages may include a tip flag (54), a serpentine channel (56), and a trailing edge channel (58). The tip flag (54) may extend radially outward along the leading edge of the rotor blade and may turn axially aftward along the tip of the rotor blade. The tip flag (54) may terminate forward of a portion of the serpentine channel (56) and the trailing edge channel (58). Thus the tip flag (54) may be a "partial tip flag." The internal passages may be arranged to ameliorate the effect of ambient pressure variations, such as between the leading edge and the trailing edge of the rotor blade, on the flow travel of cooling air through the rotor blade.