Variable Stator Vane Fabrication Using Composite Fibre Sheets

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Solution Overview

Problem

Conventional methods for fabricating stator vanes in gas turbine engines are costly and time-consuming, particularly when using metal or composite materials, as they require complex tooling and machining processes.

Innovation Solution

A method involving rolling fibre sheets around a mandrel to form spindle and aerofoil sections, using excess material to create the aerofoil sections and applying a polymeric material for impregnation, which eliminates the need for metallic spindles and reduces weight and tooling costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional casting methods are used to fabricate metal stator vanes, then manufacturing precision and strength are improved, but manufacturing cost and time consumption increase due to expensive tooling and complex processes

Engineering Contradiction:
Improvestator vane dimensional accuracyVSAvoidmanufacturing complexity
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The invention changes the material parameter from metal to composite material, and the manufacturing process parameter from casting to rolling. The fibre sheet is impregnated with polymeric material and rolled around a mandrel to form the stator vane, eliminating the need for expensive casting tooling while achieving the required manufacturing precision through the inherent properties of the composite material and rolling process

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention replaces expensive permanent casting moulds with a reusable mandrel that can be used repeatedly for rolling fibre sheets. The mandrel serves as a temporary form that is removed after fabrication, eliminating the need for costly permanent tooling while maintaining manufacturing precision

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Strength

If metal spindles are used in variable stator vanes, then structural strength is improved, but weight increases significantly

Engineering Contradiction:
Improvespindle structural strengthVSAvoidstator vane weight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The invention replaces metal spindle material with composite material (fibre sheet impregnated with polymeric material). The composite material provides sufficient structural strength while reducing weight by 40-50% compared to conventional metallic stator vanes, achieving both strength and weight reduction goals simultaneously

Inventive Principle:
Principle #40Composite materials

3Weight of moving object

If composite material is used for stator vanes, then weight is reduced, but manufacturing cost increases due to complex tooling and processes

Engineering Contradiction:
Improvestator vane weightVSAvoidmanufacturing cost
Core Design Contradiction:
Weight of moving objectVSEase of manufacture

Solution Approach 1:

The invention extracts and eliminates the expensive tooling and machining processes from the manufacturing system. By using a simple mandrel-based rolling process with fibre sheets and polymeric material, the method removes the need for costly casting moulds and subsequent machining operations, significantly reducing manufacturing cost while maintaining weight reduction benefits

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The fibre sheet with impregnated polymeric material is rolled around the mandrel to form the stator vane in a self-contained process. The excess material is used to form the aerofoil section, eliminating waste and reducing the need for additional tooling or machining steps, thereby reducing manufacturing cost

Inventive Principle:
Principle #25Self-service

4Weight of moving object

If fibre sheets are rolled around mandrels to form spindle sections, then weight and tooling cost are reduced, but manufacturing precision may be compromised

Engineering Contradiction:
Improvestator vane weightVSAvoidstator vane dimensional accuracy
Core Design Contradiction:
Weight of moving objectVSManufacturing precision

Solution Approach 1:

The fibre sheet is impregnated with polymeric material before rolling around the mandrel. This preliminary impregnation ensures proper material distribution and bonding, allowing the rolling process to achieve the required manufacturing precision without compromising dimensional accuracy, while still providing weight and tooling cost benefits

Inventive Principle:
Principle #10Preliminary action

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 method results in a cost-effective, time-efficient fabrication process that reduces the weight of variable stator vanes by 40-50% compared to conventional methods and eliminates the need for machining, while using composite materials to further reduce weight by approximately 10%.

Implementation Method 1

wherein the fibre sheet is impregnated with a polymeric material

Methodology Applied
Scientific EffectImpregnation: Absorption (physical)

Data Source

PatentEP3865667B1Variable stator vane and method of fabricating variable stator vane
Publication Date: 2023.09.27 ROLLS ROYCE PLC
  • EP3865667B1 patent drawingFigure 1
  • EP3865667B1 patent drawingFigure 2
  • EP3865667B1 patent drawingFigure 3

AI summary

The present disclosure relates to a variable stator vane (206) and a method (700) of fabricating the variable stator vane (206) of a gas turbine engine (10). The method (700) includes providing (702) at least one fibre sheet (200). The method (700) further includes rolling (704) the at least one fibre sheet (200) around a mandrel (216) to form a spindle section (210) of the variable stator vane (206). An excess of material (214) of the at least one fibre sheet (200) remains after forming the spindle section (210). The method (700) further includes using (706) the excess of material (214) of the at least one fibre sheet (200) to form the at least one aerofoil section (212) of the variable stator vane (206).