Composite Stator Vane Lightning Protection via Conductor Routing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In turbofan jet engines, stator vanes made from composite materials face challenges in withstanding lightning strikes due to high electric resistance, which can lead to spark generation, and it is difficult to ensure a controlling function while providing metal materials for lightning protection, especially in small structures like guide vanes.

Innovation Solution

A stator vane structure formed from composite materials with a metal sheath for erosion prevention and metal connecting support bodies, featuring a conductor that passes through the space between the leading edge and the sheath to connect the fan case and engine body section, allowing lightning currents to be directed safely while maintaining the controlling function and facilitating inspection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If composite material is used for stator vane, then weight is reduced and strength is improved, but lightning strike resistance deteriorates due to high electric resistance

Engineering Contradiction:
Improveweight of stator vaneVSAvoidlightning strike resistance
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

The patent employs a hybrid composite structure combining composite material (for weight reduction and strength) with metal material (for lightning strike resistance). The stator vane uses composite material for the main body while incorporating metal components at critical locations to conduct lightning currents, resolving the contradiction between weight reduction and lightning protection.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent applies different materials to different parts of the stator vane based on local requirements. The leading edge and tip portions use metal materials with high electrical conductivity for lightning protection, while the main body uses lightweight composite material. This localized material distribution optimizes both weight and lightning strike resistance.

Inventive Principle:
Principle #3Local quality

2Reliability

If metal material is added for lightning protection, then lightning strike resistance is improved, but device complexity increases

Engineering Contradiction:
Improvelightning strike resistanceVSAvoidstructural complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent integrates lightning protection function into existing structural components rather than adding separate protection systems. The connecting support bodies and leading edge covers serve both structural support functions and lightning conduction functions, eliminating the need for additional dedicated lightning protection components and reducing overall system complexity.

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

Solution Approach 2:

The patent merges the lightning protection function with existing structural elements. The metal connecting support bodies and leading edge covers that are already required for structural integrity are designed to also serve as lightning conduction paths, combining multiple functions into single components and avoiding increased complexity.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If metal material is added for lightning protection, then lightning strike resistance is improved, but manufacturing difficulty increases

Engineering Contradiction:
Improvelightning strike resistanceVSAvoidmanufacturing ease
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent incorporates lightning protection features during the initial manufacturing process rather than adding them later. The metal leading edge covers and connecting support bodies are manufactured and positioned during assembly, with conductor paths established as part of the primary manufacturing sequence, avoiding complex post-manufacturing modifications.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent nests the conductor path within the existing structural hierarchy. The conductor is positioned within the leading edge cover structure and connected through the connecting support bodies, with each component manufactured separately and then assembled in a nested configuration that simplifies the overall manufacturing process.

Inventive Principle:
Principle #7Nested doll (Nesting)

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 enables effective protection against lightning strikes while ensuring lightweight, high-strength, and durable stator vanes with easy inspection capabilities, maintaining the controlling function and preventing spark generation.

Implementation Method 1

a conductor that passes through a space between the leading edge section of the stator vane and the metal for erosion prevention, and connects the connecting support bodies at the first end and second end

Methodology Applied
Scientific EffectLightning current conduction: Conduction (electrical)

Implementation Method 2

a metal for erosion prevention that covers at least a leading edge section of the stator vane

Methodology Applied
Scientific EffectAbrasion resistance: Abrasion

Data Source

PatentEP3018363B1Stator vane structure and turbofan jet engine using same
Publication Date: 2019.11.13 IHI CORP
  • EP3018363B1 patent drawingFigure 1
  • EP3018363B1 patent drawingFigure 2A~2B
  • EP3018363B1 patent drawingFigure 3A~3B

AI summary

A distal end portion (21) and a proximal end portion (22) of a guide vane (20) formed from a composite material are respectively supported by connecting support bodies (30, 31) formed from a metal, and the connecting support bodies (30, 31) of the distal end portion (21) and the proximal end portion (22) are connected by a conductive wire (40) while the conductive wire (40) is passed through a space between a leading edge surface (20a) of the guide vane (20) and a sheath (23). In a turbofan jet engine, a lightning current due to a lightning strike can be fended off while a controlling function of a stator vane formed from a composite material is ensured, and an inspection is also easy.