Gas Turbine Blade Cross-Ties for Vibration Reduction

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Solution Overview

Problem

Gas turbine engine components, such as airfoils, face high stress and limited operational life due to lack of structural support during operation, as conventional manufacturing methods do not provide continuous support after removal of stiffening rods.

Innovation Solution

The method involves fabricating blade elements with cross-ties, which are structural elements with a curved profile blended into the inner walls, providing rigidity and support to unsupported areas without restricting airflow or heat transfer, and are formed integrally during the manufacturing process using a cast with negatives and positives to include cross-ties and cooling passages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of stationary object

If conventional manufacturing methods using stiffening rods are used, then component fabrication is simple, but structural support and operational life are limited

Engineering Contradiction:
Improveoperational lifeVSAvoidstructural support system
Core Design Contradiction:
Duration of action of stationary objectVSDevice complexity

Solution Approach 1:

The blade element is divided into multiple sections connected by cross-ties, creating segmented structural support throughout the passage rather than relying on a single continuous stiffening rod. This segmentation provides distributed support that maintains structural integrity while enabling longer operational life.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cross-ties are integrated directly into the passage structure, merging the support function with the passage geometry. Unlike separate stiffening rods that must be installed and removed, the cross-ties are formed as part of the passage itself, eliminating the need for separate support components while providing continuous structural reinforcement.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If cross-ties are added to provide structural support, then operational life is extended, but manufacturing complexity increases

Engineering Contradiction:
Improvestructural integrityVSAvoidfabrication process
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The cross-ties are formed during the initial casting process rather than being added as separate components afterward. The mold includes features that create the cross-tie geometry as the passage is being formed, so the structural support elements are prepared in advance along with the passage itself, eliminating subsequent assembly steps.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The mold serves as an intermediary tool that simultaneously creates both the passage and the cross-ties. By designing the mold with specific geometries, the cross-ties are automatically formed as part of the casting process, translating complex structural requirements into a straightforward manufacturing operation.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Strength

If cross-ties are formed integrally with the passage, then structural support is continuous, but mold design becomes more complex

Engineering Contradiction:
Improvestructural supportVSAvoidmold design
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The cross-ties extend in the axial dimension of the passage, adding structural support along the length of the passage rather than only across the cross-section. This dimensional approach allows the cross-ties to connect opposite walls of the passage along its entire length, providing continuous support that distributes stress throughout the blade element.

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

Solution Approach 2:

The cross-ties are formed with curved profiles that blend smoothly into the passage walls, following the contours of the passage geometry. This curvature allows the cross-ties to integrate seamlessly with the passage structure, providing structural support while maintaining aerodynamic smoothness and eliminating stress concentration points.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Data Source

PatentEP2942484B2Blade element cross-ties
Publication Date: 2023.05.03 RTX CORP
  • EP2942484B2 patent drawingFigure 1A~1B
  • EP2942484B2 patent drawingFigure 1C
  • EP2942484B2 patent drawingFigure 2A~2B

AI summary

The invention concerns a blade element for a gas turbine engine and methods of manufacturing said blade elements. In one embodiment, a blade element 100 includes a first inner surface 108 of the blade element, wherein the first inner surface 108 is associated with a first outer blade surface 106 of the blade element, and a second inner surface 109 of the blade element, wherein the second inner surface 109 is associated with a second outer blade surface 107 of the blade element and wherein the second inner surface 109 is opposite from the first inner surface 108. The blade element 100 also includes a cross-tie 1301 configured to connect the first inner surface 108 to the second inner surface 109, wherein the cross-tie 1301 is positioned along a trailing edge 110 of the blade element 100 and the cross-tie 1301 is configured to reduce vibration mode effects of the blade element 100.