Trailing Edge Cooling Pedestals for Gas Turbine Airfoils

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Solution Overview

Problem

Gas turbine engine components in hot sections face increased stress and wear due to high gas path temperatures and pressures, requiring effective cooling to prevent damage, but existing cooling methods often compromise engine efficiency by increasing cooling flow requirements.

Innovation Solution

An improved cooling configuration for gas turbine engine components, including rotor and stator airfoils, utilizing internal cooling passages and optimized cooling holes with metering and inlet geometry to reduce flow requirements, and the use of pedestals in the trailing edge region to enhance convective heat transfer and minimize mixing losses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If existing cooling methods are used for gas turbine engine components, then thermal protection is provided, but engine efficiency is compromised by increased cooling flow requirements

Engineering Contradiction:
Improvethermal protectionVSAvoidengine efficiency
Core Design Contradiction:
TemperatureVSLoss of energy

Solution Approach 1:

The invention changes the geometric parameters of cooling holes (aspect ratio, inlet area, outlet area) and internal passage configuration to optimize cooling effectiveness. By adjusting these parameters, the cooling system achieves better thermal protection with reduced cooling flow requirements, thus maintaining engine efficiency while protecting components from high temperatures

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention applies different cooling hole configurations and internal passage designs to specific regions of the airfoil based on local thermal requirements. The trailing edge region receives enhanced cooling through optimized hole geometry and pedestal structures, while other regions use appropriate cooling configurations, allowing efficient thermal management with minimized overall cooling flow

Inventive Principle:
Principle #3Local quality

2Reliability

If cooling flow requirements are increased to protect components, then thermal fatigue is reduced, but engine performance deteriorates

Engineering Contradiction:
Improvethermal fatigue resistanceVSAvoidengine performance
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

By optimizing the geometric parameters of cooling holes and internal passages, the invention enhances cooling effectiveness in critical regions such as the trailing edge. This localized optimization provides superior thermal fatigue resistance without requiring increased overall cooling flow, thereby maintaining engine performance and productivity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The cooling system is segmented into multiple cooling holes and internal passages distributed throughout the airfoil structure. This segmentation allows targeted cooling of high-stress regions like the trailing edge while reducing cooling requirements in less critical areas, achieving reliable thermal protection without compromising engine performance

Inventive Principle:
Principle #1Segmentation

3Ease of manufacture

If conventional cooling hole geometry is used, then manufacturing is simplified, but convective heat transfer effectiveness is reduced

Engineering Contradiction:
Improvecooling hole fabricationVSAvoidconvective heat transfer
Core Design Contradiction:
Ease of manufactureVSTemperature

Solution Approach 1:

The invention modifies the geometric parameters of cooling holes including aspect ratio, inlet area, and outlet area to enhance convective heat transfer. These parameter changes improve cooling effectiveness while remaining compatible with conventional manufacturing processes such as drilling and machining, thus maintaining ease of manufacture while achieving superior thermal performance

Inventive Principle:
Principle #35Parameter changes

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, increases service life, and maintains engine efficiency by optimizing cooling fluid distribution and reducing flow separation, resulting in improved reliability and performance.

Implementation Method 1

internal cooling passages and optimized cooling holes with metering and inlet geometry to reduce flow requirements

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 2

effectively reduces thermal fatigue, increases service life, and maintains engine efficiency by optimizing cooling fluid distribution

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 3

the use of pedestals in the trailing edge region to enhance convective heat transfer and minimize mixing losses

Methodology Applied
Scientific EffectConvective heat transfer: Convection

Implementation Method 4

minimize mixing losses

Methodology Applied
Scientific EffectFlow separation: Flow Separation

Data Source

PatentEP2828514B1Trailing edge cooling
Publication Date: 2020.01.01 UNITED TECH CORP
  • EP2828514B1 patent drawingFigure 1
  • EP2828514B1 patent drawingFigure 2A
  • EP2828514B1 patent drawingFigure 2B

AI summary

An airfoil includes a leading edge, a trailing edge, a suction surface, a pressure surface, a cooling passageway, and a plurality of oblong pedestals. The suction surface and the pressure surface both extend axially between the leading edge and the trailing edge, as well as radially from a root section to a tip section of the airfoil. The cooling passageway is located between the suction surface and the pressure surface. The oblong pedestals connect the suction surface to the pressure surface at the trailing edge of the airfoil.