Variable Area Vane Cooling Air Segmentation

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 arrangement.

Innovation Solution

The design incorporates an adjustable stator vane with a shaft, flange, and stator vane body that pivots about a variable vane axis, featuring a cavity and cooling apertures to manage cooling air effectively while minimizing the size of the bearing and weight, using a flange that extends circumferentially around the shaft and radially from the stator vane body, reducing the need for a large outer shaft bore.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

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

Engineering Contradiction:

Improvecooling effectivenessVSAvoidbearing weight

Core Design Contradiction:

TemperatureVSWeight of moving object

Solution Approach 1:

The cooling air delivery system is segmented into multiple smaller bores within the outer shaft instead of using a single large bore. This allows sufficient total cooling air flow while maintaining a smaller outer shaft diameter and smaller bearing size, resolving the contradiction between cooling effectiveness and bearing weight.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Multiple cooling air bores are nested within the outer shaft structure. This nested arrangement provides sufficient cooling air flow paths while keeping the overall outer shaft diameter small, thereby reducing bearing size and weight while maintaining cooling effectiveness.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Temperature

If the outer shaft bore diameter is increased to provide sufficient cooling air, then the cooling effectiveness is improved, but the complexity of the vane arrangement increases

Engineering Contradiction:

Improvecooling effectivenessVSAvoidvane arrangement complexity

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The cooling air delivery system is segmented into multiple smaller bores within the outer shaft instead of using a single large bore. This allows sufficient total cooling air flow while maintaining a smaller outer shaft diameter and smaller bearing size, resolving the contradiction between cooling effectiveness and bearing weight.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Multiple cooling air bores are nested within the outer shaft structure. This nested arrangement provides sufficient cooling air flow paths while keeping the overall outer shaft diameter small, thereby reducing bearing size and weight while maintaining cooling effectiveness.

Inventive Principle:

Principle #7Nested doll (Nesting)

3Object-generated harmful factors

If the flange is positioned closer to the airfoil surface to reduce gap leakage, then gas leakage is reduced, but the cooling air flow to the airfoil is restricted

Engineering Contradiction:

Improvegas leakageVSAvoidcooling air flow

Core Design Contradiction:

Object-generated harmful factorsVSQuantity of substance

Solution Approach 1:

The flange structure is segmented with radial gaps between the flange and airfoil surface. These segmented gaps allow cooling air to pass through to the airfoil cooling surfaces while the flange structure itself blocks hot gas leakage paths, simultaneously achieving both cooling air delivery and gas leakage prevention.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The flange structure has different local functions: the main flange body blocks hot gas leakage, while controlled radial gaps in specific locations allow cooling air flow. This local differentiation of function resolves the contradiction between preventing gas leakage and allowing cooling air flow.

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 configuration enhances the efficiency and reliability of the variable area vane arrangement by maintaining effective cooling while reducing weight and complexity, thereby improving the overall performance and reducing gas leakage during pivoting.

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

An outer radial end of each stator vane is rotatably connected to the outer vane platform with an outer shaft and a bearing

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentUS10215048B2Variable area vane arrangement for a turbine engine

Publication Date: 2019.02.26 RTX CORP

AI summary

An adjustable stator vane for a turbine engine includes a shaft, a flange and a stator vane body that pivots about a variable vane axis. The stator vane body extends axially between a first end and a second end. The stator vane body includes an airfoil, a cavity, and a body surface 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 around the inlet and the shaft, and radially from the stator vane body.