Multi-segment Stator Vane Cooling Air Extraction

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Solution Overview

Problem

Existing variable area vane arrangements in turbine engines face challenges with increased weight, cost, and complexity due to the large diameter of outer shafts required for sufficient cooling air, which affects the efficiency and reliability of the vane mechanisms.

Innovation Solution

The design incorporates a flange and seal system that extends circumferentially around the shaft and inlet, with cooling apertures and channels to direct cooling air effectively, reducing the need for a large outer shaft diameter while maintaining efficient cooling and reducing gas leakage during vane pivoting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the outer shaft bore diameter is increased to provide sufficient cooling air, then the cooling air quantity is improved, but the bearing size and weight increase

Engineering Contradiction:
Improvecooling air quantityVSAvoidbearing weight
Core Design Contradiction:
Quantity of substanceVSWeight of moving object

Solution Approach 1:

The patent extracts the cooling air supply function from the outer shaft bore and relocates it to a separate plenum chamber and dedicated cooling air passages. This allows the outer shaft bore to be minimized for bearing support while the plenum chamber provides sufficient cooling air through separate passages that deliver air directly to the airfoil surfaces.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a plenum chamber as an intermediary component between the cooling air source and the airfoil surfaces. This plenum chamber receives cooling air and distributes it through dedicated passages to the airfoil leading edge, trailing edge, and suction surface, separating the cooling air supply function from the shaft structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Quantity of substance

If the outer shaft bore diameter is increased to provide sufficient cooling air, then the cooling air quantity is improved, but the device complexity increases

Engineering Contradiction:
Improvecooling air quantityVSAvoidvane arrangement complexity
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent extracts the cooling air distribution system from the outer shaft and creates a separate plenum chamber with dedicated passages. This separation allows each component to be optimized for its specific function: the shaft for mechanical support and the plenum chamber for cooling air management, thereby reducing overall system complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The plenum chamber serves multiple functions: it collects cooling air from the compressor, distributes it through multiple passages to different airfoil surfaces (leading edge, trailing edge, suction surface), and maintains proper pressure distribution. This multi-functionality consolidates what would otherwise require multiple separate systems.

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

3Reliability

If cooling air is directed effectively with flange and seal system, then cooling efficiency is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvecooling efficiencyVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The vane assembly is segmented into distinct components: the airfoil, the flange, the seal, and the cooling passages. This segmentation allows each component to be manufactured separately with optimized geometries and then assembled, improving cooling efficiency while managing manufacturing complexity through modular production.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cooling passages are pre-formed within the flange and airfoil structures during manufacturing, and the seal is pre-installed in the flange groove before final assembly. This preliminary preparation of cooling paths and sealing surfaces ensures proper cooling efficiency while simplifying the final assembly process.

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 design enhances the efficiency of cooling and reduces weight and complexity by optimizing the cooling air distribution, improving the overall performance and reliability of the variable area vane arrangement in turbine engines.

Implementation Method 1

Airfoil cooling apertures may subsequently direct the cooling air out of the cavity to film cool the outer surfaces of the airfoil that are exposed to the core gas

Methodology Applied
Scientific EffectFilm cooling: Cooling

Implementation Method 2

The flange may extend circumferentially around the shaft. The assembly may include a seal that extends circumferentially, partially around the shaft, between a seal first end and a seal second end

Methodology Applied
Scientific EffectSealing:

Data Source

PatentEP2948642B1Multi-segment adjustable stator vane for a variable area vane arrangement
Publication Date: 2020.10.21 RTX CORP
  • EP2948642B1 patent drawingFigure 1~2
  • EP2948642B1 patent drawingFigure 3
  • EP2948642B1 patent drawingFigure 4~5

AI summary

An assembly for a turbine engine includes a plurality of vane segments. The vane segments are fastened together and form an adjustable stator vane that pivots about a variable vane axis. The adjustable stator vane includes a stator vane body, a shaft and a flange. The stator vane body extends axially between a first end and a second end, and includes an airfoil, a body surface and a cavity. The body surface is located at the first end. The cavity extends axially from an inlet in the body surface and into the airfoil. The shaft extends along the variable vane axis from the first end. The flange extends circumferentially at least partially around the inlet, and radially from the stator vane body. A first of the vane segments includes the flange. A second of the vane segments includes at least a portion of the airfoil.