Gas Turbine Igniter Cable Conduit Aerodynamic Perforations

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Solution Overview

Problem

Gas turbine engine igniter cables exposed to harsh bypass flow environments face damage and degradation due to impact and differential thermal growth between engine components, leading to reduced operational life.

Innovation Solution

A cable conduit system comprising a head end, sleeve, boot, and split grommet with aerodynamic perforations and a circumferential channel, allowing bypass flow to pass through and accommodating thermal expansion, coupled to the outer and combustor cases to minimize turbulence and vortices, and featuring a sleeve locking mechanism to secure the conduit.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-generated harmful factors

If the cable conduit allows bypass flow to pass through via perforations, then turbulence and vortices are reduced, but the structural integrity and protection from impact may be compromised

Engineering Contradiction:
Improveturbulence and vorticesVSAvoidstructural integrity
Core Design Contradiction:
Object-generated harmful factorsVSStrength

Solution Approach 1:

The cable conduit incorporates a perforated structure with multiple holes that allow bypass flow to pass through while maintaining overall structural integrity. The porous design reduces turbulence and vortices by enabling smooth flow transition, yet the material and structural configuration preserve sufficient strength to protect cables from impact.

Inventive Principle:
Principle #31Porous materials

2Manufacturing precision

If the cable conduit is rigidly coupled to engine components, then positioning is precise, but differential thermal growth causes damage and reduces operational life

Engineering Contradiction:
Improvepositioning precisionVSAvoidoperational life
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The cable conduit employs flexible coupling mechanisms and resilient mounting structures that allow controlled movement and expansion. This dynamic design accommodates differential thermal growth between engine components while maintaining precise positioning during normal operation, thereby preventing damage and extending operational life.

Inventive Principle:
Principle #15Dynamics

3Reliability

If the cable conduit provides comprehensive protection from impact, then cable reliability improves, but the ability to accommodate thermal expansion is reduced

Engineering Contradiction:
Improvecable protectionVSAvoidthermal expansion accommodation
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The cable conduit utilizes flexible protective coverings and resilient structural elements that provide impact protection while allowing controlled deformation. These flexible components absorb thermal expansion forces and protect cables from mechanical impact, achieving both protection and adaptability simultaneously.

Inventive Principle:
Principle #30Flexible shells and thin films

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 cable conduit system reduces turbulence and vortices around the cables, protects them from impact, and accommodates thermal growth, thereby extending the operational life of the cables and maintaining efficient bypass flow.

Implementation Method 1

a forward aerodynamic surface comprising a plurality of perforations. The forward aerodynamic surface, the aft aerodynamic surface, and the cable conduit are configured to reduce turbulence and vortices around the cable conduit as bypass flow passes over the cable conduit

Methodology Applied
Scientific EffectBypass flow: Convection

Implementation Method 2

The boot is configured to accommodate differential thermal growth between a forward engine component and an aft engine component

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP3483398B1Igniter cable conduit and assembly method
Publication Date: 2021.12.29 RTX CORP
  • EP3483398B1 patent drawingFigure 1A
  • EP3483398B1 patent drawingFigure 1B
  • EP3483398B1 patent drawingFigure 2

AI summary

A cable conduit (200) may comprise a head end (216), a sleeve (205) having a foot end (218), a boot (206), and a split grommet (222) having a first upper surface, wherein the head end (216) is coupled to the sleeve (205) opposite the foot end (218), wherein the boot (206) comprises a first flange (208) and is coupled to the foot end (218), wherein the head end (216) comprises a second flange (210) having a second upper surface (212) and a cutout (220) penetrating into an interior volume of the sleeve (205), and wherein the split grommet (222) is coupled about the inner diameter of the cutout (220).