Composite Guide Vane Mounting for Low-Bulk Unducted Fan Engines

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Solution Overview

Problem

Existing attachment methods for fixed blades made of composite materials in turbomachines require large fixing surfaces, either radially or tangentially, which limits integration and complicates manufacturing.

Innovation Solution

A fixed blade design with a single internal platform extending tangentially and a monobloc piece construction, combined with a reinforcing element, reduces the tangential footprint and simplifies the manufacturing process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If radial flanges are used to fix the fixed blade platform to the fixed structure, then the second moment of area is improved and force transfer is enhanced, but the fixing surface area requirement increases significantly

Engineering Contradiction:
Improveforce transfer capabilityVSAvoidfixing surface area
Core Design Contradiction:
StrengthVSArea of stationary object

Solution Approach 1:

The patent applies asymmetry by transitioning from symmetric radial flanges extending in both tangential directions to a single internal platform extending in only one tangential direction. This asymmetric configuration reduces the fixing surface area while maintaining structural integrity through strategic placement of the platform away from the blade, preserving the second moment of area for effective force transfer.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent positions the internal platform at a radial distance from the blade, utilizing the radial dimension to optimize the second moment of area. By extending the platform tangentially from the blade foot rather than using radial flanges, the solution transfers forces effectively through spatial arrangement in multiple dimensions while minimizing the overall fixing surface area.

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

2Area of stationary object

If a tangential attachment is used to secure the fixed stator blade, then the tangential space requirement is limited, but the radial space requirement increases significantly

Engineering Contradiction:
Improvetangential spaceVSAvoidradial space
Core Design Contradiction:
Area of stationary objectVSLength of moving object

Solution Approach 1:

The patent segments the fixed blade structure into distinct functional components: an aerodynamic blade portion and a separate internal platform portion. This segmentation allows the platform to be positioned optimally for minimal radial space occupation while providing sufficient tangential extension for secure attachment, effectively separating the aerodynamic function from the mounting function.

Inventive Principle:
Principle #1Segmentation

3Weight of moving object

If fixed blades are made of composite materials with reduced weight, then the blade weight is decreased while maintaining mechanical properties, but the attachment complexity to metal stator parts increases

Engineering Contradiction:
Improveblade weightVSAvoidattachment complexity
Core Design Contradiction:
Weight of moving objectVSDevice complexity

Solution Approach 1:

The patent merges the composite aerodynamic blade and the metal internal platform into a single integrated fixed blade assembly. This merging eliminates the need for separate attachment mechanisms between composite blades and metal stator parts, reducing attachment complexity while maintaining the weight benefits of composite materials through the unified structure.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP4508312B1Turbomachine engine with unducted fan
Publication Date: 2026.01.21 SAFRAN AIRCRAFT ENGINES SAS
  • EP4508312B1 patent drawingFigure 1

AI summary

The invention relates to a turbine engine motor having an unducted fan, the motor comprising a plurality of guide vanes (10) made of composite materials. Each of the guide vanes is intended to be fixed only to an inner fixed structure (20) of the turbine engine. The guide vane (10) comprises: an aerodynamic airfoil (12) which extends radially outwards along a radial axis (X-X); an outer radial end (14); an inner radial end (16); and an inner platform (18) which is configured to be fixed to the inner fixed structure (20), is attached to the inner radial end (16) by an inner attachment elbow (16a) and extends from the inner radial end (16) in a single first tangential direction secant to the radial axis (X-X) of the aerodynamic airfoil (12). The inner platform (18) comprises an opening (18a) for receiving a radial fixing system (30) for independently fixing each of the guide vanes to the inner fixed structure (20). A reinforcement element is arranged radially between the inner platform (18) of each of the guide vanes (10) and the inner fixed structure (20).