3D Chevron Pedestals for Gas Turbine Cooling

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Solution Overview

Problem

The manufacturing limitations of internal cooling features in gas turbine components, such as pedestals in stamped metallic cores, restrict the orientation of cooling features to be normal to the cavity flow direction, which can limit the effectiveness of heat transfer augmentation in high-temperature environments.

Innovation Solution

The use of additive manufacturing to create 3D swept turbulators with non-linear profiles and chevron geometries in internal cooling passages, allowing for more adaptive and effective heat transfer enhancement by generating vertical structures that disrupt the boundary layer and increase heat transfer rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If traditional stamped metallic cores with pedestals are used, then manufacturing is simpler, but the cooling features are restricted to normal orientation relative to cavity flow direction, limiting heat transfer effectiveness

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidcooling feature orientation precision
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The invention changes the manufacturing method from traditional stamped metallic cores to additive manufacturing, enabling pedestals to be oriented at various angles (15-45 degrees) relative to the cavity flow direction rather than being restricted to normal orientation. This parameter change in manufacturing approach allows optimization of heat transfer effectiveness while maintaining manufacturing feasibility.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention introduces angular orientation as an additional design dimension for pedestal placement. Instead of only normal orientation to the flow direction, pedestals can now be positioned at specific angles (15-45 degrees), adding rotational freedom to the design space and enabling better heat transfer augmentation.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Temperature

If more cooling air is extracted from the compressor, then turbine component cooling is improved, but cycle efficiency deteriorates due to significant cycle penalties

Engineering Contradiction:
Improveturbine component temperatureVSAvoidcycle efficiency
Core Design Contradiction:
TemperatureVSLoss of energy

Solution Approach 1:

The invention changes the heat transfer coefficient parameter by optimizing pedestal geometry and orientation, allowing for reduced cooling air extraction while maintaining effective cooling. This enables better thermal management with lower energy penalties.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses computational fluid dynamics (CFD) modeling to create virtual copies and simulations of cooling passages, allowing optimization of cooling effectiveness before physical manufacturing. This reduces the need for extensive physical testing and iteration, saving energy and time.

Inventive Principle:
Principle #26Copying

3Temperature

If internal cooling circuits with numerous film cooling holes are used, then airfoil cooling is improved, but device complexity increases

Engineering Contradiction:
Improveairfoil cooling effectivenessVSAvoidcooling circuit complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The invention applies local quality by placing pedestals at specific locations and orientations within the cooling passages where they can most effectively augment heat transfer. This localized optimization allows for reduced overall cooling system complexity while maintaining effective cooling.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention uses curved or swept pedestal geometries that follow the flow patterns within cooling passages, optimizing heat transfer effectiveness while simplifying the overall cooling circuit design compared to numerous straight film cooling holes.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 approach enables more robust and efficient heat transfer within gas turbine components, reducing the need for costly tooling and allowing for intricate designs that enhance cooling performance, thereby improving the overall efficiency of gas turbine engines.

Implementation Method 1

generating vertical structures that disrupt the boundary layer and increase heat transfer rates

Methodology Applied
Scientific EffectBoundary layer disruption: Boundary Layer

Implementation Method 2

3D swept turbulators with non-linear profiles and chevron geometries in internal cooling passages, allowing for more adaptive and effective heat transfer enhancement

Methodology Applied
Scientific EffectTurbulence: Turbulence

Data Source

PatentEP3287598B1Cooling features with three dimensional chevron geometry
Publication Date: 2020.09.30 RTX CORP
  • EP3287598B1 patent drawingFigure 1
  • EP3287598B1 patent drawingFigure 2
  • EP3287598B1 patent drawingFigure 3

AI summary

The present invention is related to n internally cooled component such as an airfoil (100) of a gas turbine engine (20). The airfoil (100) includes an internal cooling system (300) comprising an internal cooling passage (108) with a first and a second pedestal (304,306). The first pedestal (304) has a chevron geometry as well as the second pedestal (306) has a chevron geometry. A gap (305) may be defined by the first pedestal (304) and the second pedestal (306) with the gap (305) oriented between the first pedestal (304) and the second pedestal (306). The pedestals (304,306) may be inclined with respect to an axial direction (420), thereby forming a third chevron geometry. Thus, internal cooling efficiency is enhanced because the 3D chevron features tend to increase the overall turbulent intensity of the cooling channel and augment the effectiveness of downstream heat transfer promoters.