Gas Turbine Airfoil Cooling via Segmented Skin Cores

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Solution Overview

Problem

The leading edge of internally-cooled airfoils in gas turbine engines, such as turbine blades and vanes, is particularly difficult to cool, especially when the external wall is damaged, as existing cooling methods are inadequate in providing effective heat transfer and redundancy in such scenarios.

Innovation Solution

The airfoil design incorporates multiple skin cores with heat transfer augmentation features like trip strips and an embedded core with additional heat transfer augmentation features, which provide enhanced convective heat transfer and redundancy for cooling, even if the external wall is damaged.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If internal convection cooling is used via internal cavities, then cooling capability is improved, but reliability deteriorates when external wall is damaged

Engineering Contradiction:
Improvecooling capabilityVSAvoidcooling effectiveness
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The airfoil is divided into multiple independent cooling zones with separate skin cores (first skin core, second skin core, third skin core) that can function independently. Each skin core has its own cooling channels, allowing the cooling system to remain effective even if one zone is compromised by external wall damage.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The embedded core is positioned inside the airfoil body as a pre-positioned backup cooling system. This redundant cooling pathway is designed in advance to activate or provide support when the external wall structure is damaged, ensuring continuous cooling capability without requiring real-time detection of damage.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Strength

If external wall structure is present, then structural integrity is improved, but heat transfer effectiveness deteriorates when wall is damaged

Engineering Contradiction:
Improvestructural integrityVSAvoidheat transfer effectiveness
Core Design Contradiction:
StrengthVSTemperature

Solution Approach 1:

Different regions of the airfoil are equipped with different cooling configurations. The skin cores are positioned at specific locations (leading edge, pressure side, suction side) with tailored cooling channels and heat transfer augmentation features appropriate for each region's thermal and mechanical requirements.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The airfoil employs a composite structure combining the external wall structure with internal cooling channels and heat transfer augmentation features. This integrated design allows the structure to simultaneously provide mechanical strength and enhanced heat transfer capability through features like trip strips that promote turbulent flow and improve convective cooling.

Inventive Principle:
Principle #40Composite materials

3Reliability

If multiple skin cores are added, then redundancy is improved, but device complexity increases

Engineering Contradiction:
Improvecooling redundancyVSAvoidcooling system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Multiple cooling functions are merged into a unified airfoil structure. The external wall structure, internal cooling channels, and heat transfer augmentation features are integrated into a single component rather than being separate assemblies, reducing overall system complexity while maintaining multiple cooling pathways.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The embedded core serves multiple functions: it provides structural support to the airfoil body, acts as a backup cooling pathway, and contains heat transfer augmentation features. This multi-functionality reduces the need for separate dedicated components, thereby reducing overall system complexity despite the added redundancy.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 effectively enhances cooling capabilities and provides redundancy to maintain efficient heat transfer and cooling performance even if the external wall is compromised, ensuring continued operation and performance of the airfoil.

Implementation Method 1

cooling air from the compressor can be routed to provide internal convection cooling via internal cavities within airfoils

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 2

The skin cores may include heat transfer augmentation features, such as an array of trip strips, to enhance convective heat transfer

Methodology Applied
Scientific EffectHeat transfer augmentation: Turbulence

Data Source

PatentEP3379032B1Cooled airfoil and corresponding gas turbine engine
Publication Date: 2021.06.30 RTX CORP
  • EP3379032B1 patent drawingFigure 1
  • EP3379032B1 patent drawingFigure 2
  • EP3379032B1 patent drawingFigure 3

AI summary

An airfoil (100) may include an external airfoil surface (105) and an airfoil body (110). The airfoil body (110) may include an external wall structure (114) and an internal wall structure (116). The external airfoil surface (105) may be adjacent the external wall structure (114). The airfoil body (110) may define a skin core (121) that is at least partially defined by a first section (141) of the external wall structure (114) and a first section (161) of the internal wall structure (116). The airfoil body (110) may also define an embedded core (130) that is at least partially defined by the first section (161) of the internal wall structure (116). An embedded core heat transfer augmentation feature (170) may be formed within the embedded core (130) on an embedded core surface of the first section (161) of the internal wall structure (116).