Stator Vane Cooling Passage Studs for Lower-Cost Machining

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Solution Overview

Problem

The manufacturing of outlet guide vanes with integrated heat exchanger functions in dual-flow aircraft turbomachines is costly and time-consuming due to conventional machining techniques, and alternative methods like electroerosion incur significant tooling costs.

Innovation Solution

The use of a bell-shaped milling cutter to create flow disturbing studs within the internal lubricant cooling passages of the guide vanes, facilitating the machining process and reducing manufacturing costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional machining techniques are used to manufacture guide vanes with integrated heat exchangers, then manufacturing precision can be maintained, but manufacturing cost and production time increase significantly

Engineering Contradiction:

Improvemanufacturing precisionVSAvoidmanufacturing cost

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent replaces conventional mechanical machining processes with a specialized bell-shaped milling cutter that creates flow disturbing studs in a single operation. This substitution eliminates the need for multiple machining steps, significantly reducing manufacturing time and cost while maintaining the required precision for heat exchanger passages.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Shape

If electrical discharge machining is used to create flow disturbing studs, then complex geometries can be achieved, but tooling cost increases significantly

Engineering Contradiction:

Improvegeometry complexityVSAvoidtooling cost

Core Design Contradiction:

ShapeVSEase of manufacture

Solution Approach 1:

The patent employs a specialized bell-shaped milling cutter that is simpler and less expensive than EDM tooling. The cutter creates the required flow disturbing stud geometries through conventional machining, avoiding the high tooling costs associated with electrical discharge machining while achieving the necessary geometric complexity.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Manufacturing precision

If multiple machining operations are used to create flow disturbing studs, then manufacturing precision can be maintained, but production time increases

Engineering Contradiction:

Improvemanufacturing precisionVSAvoidproduction time

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The patent combines multiple machining operations into a single step using a bell-shaped milling cutter with specific geometric features. The cutter simultaneously creates the flow disturbing studs and maintains passage dimensions within tolerance, eliminating sequential operations and significantly reducing production time while preserving manufacturing precision.

Inventive Principle:

Principle #5Merging (Combining)

4Temperature

If flow disturbing studs are added to internal passages, then heat exchange performance is improved, but manufacturing complexity increases

Engineering Contradiction:

Improveheat exchange performanceVSAvoidmanufacturing complexity

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The patent applies flow disturbing studs only in specific locations within the internal passages where they most effectively enhance heat exchange. The bell-shaped milling cutter is designed to create these localized features without requiring complex tooling or multi-step processes, thus improving heat transfer while minimizing manufacturing complexity.

Inventive Principle:

Principle #3Local quality

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 simplifies the manufacturing of guide vanes with integrated heat exchangers, reducing production time and costs while maintaining effective heat exchange performance.

Implementation Method 1

The use of a bell-shaped milling cutter to create flow disturbing studs within the internal lubricant cooling passages of the guide vanes, facilitating the machining process

Methodology Applied

Scientific EffectMachining: Abrasion

Implementation Method 2

This function involves heat exchange between the outside air passing through the ring of outlet guide vanes and the lubricant circulating inside these vanes

Methodology Applied

Scientific EffectHeat exchange: Convection

Data Source

PatentEP3610134B1Stator vane, corresponding turbomachine and manufacturing method

Publication Date: 2021.03.10 SAFRAN AIRCRAFT ENGINES SAS

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Figure 2a~3
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AI summary

The invention relates to a guide vane intended to be arranged in all or part of an air flow of an aircraft bypass turbomachine fan, the vane comprising an aerodynamic part equipped with at least one interior lubricant cooling passage (50a) delimited in part by an intrados wall and an extrados wall (72) of the vane, there being flow-disturbing lugs (80), made as one piece with one of the intrados and extrados walls (72), passing across the passage. According to the invention, in any plane of section passing orthogonally through the lugs (80), the space (94) defined between these lugs has a geometry defined exclusively by a set of annulus shapes (92) of the same dimensions, partially overlapping one another and each in part delimiting at least two of these lugs (80).