VIGV Shielding by ESS Vanes in Gas Turbine Engines

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Solution Overview

Problem

Gas turbine engines face inefficiencies and performance issues due to icing on components like vanes, which can alter geometry, reduce efficiency, and cause damage from ice shedding, and existing anti-icing systems add weight and complexity with additional hardware requirements.

Innovation Solution

The positioning of Variable Inlet Guide Vanes (VIGVs) relative to Engine Section Stator (ESS) vanes creates low droplet concentration regions, shielding VIGVs from ice buildup by positioning them radially outer to be protected by ESS vanes, reducing ice formation and shedding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If conventional anti-icing systems (hot air bleeds, heating elements) are used to prevent ice formation on VIGVs, then ice accumulation is reduced, but device complexity and weight increase due to additional hardware

Engineering Contradiction:

Improveice accumulation on VIGVsVSAvoidhardware complexity of anti-icing system

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The invention utilizes the harmful ice-forming moisture in the atmosphere to its advantage by positioning VIGVs in regions where this moisture naturally accumulates through aerodynamic processes. The ESS vanes create a shielding effect that directs moisture-laden flow away from VIGVs, converting the harmful environmental condition into a protective mechanism that reduces ice accumulation without requiring active anti-icing hardware

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The engine's existing aerodynamic flow patterns and component geometry (ESS vanes and core duct configuration) are leveraged to create self-protecting flow regions. The system uses its own operational characteristics - the fan-generated airflow and vane-induced flow separation - to automatically shield VIGVs from icing conditions without requiring external anti-icing systems

Inventive Principle:

Principle #25Self-service

2Object-affected harmful factors

If hot air bleeds and ducting are added to protect VIGVs from icing, then ice formation is prevented, but weight increases due to additional components

Engineering Contradiction:

Improveice formation on VIGVsVSAvoidengine weight

Core Design Contradiction:

Object-affected harmful factorsVSWeight of moving object

Solution Approach 1:

The invention converts the naturally occurring aerodynamic flow patterns and moisture distribution in the engine inlet into a protective mechanism. By positioning VIGVs in regions where flow separation and shielding naturally occur behind ESS vanes, the system uses the engine's own operational characteristics to create ice-free zones without requiring weight-intensive heating systems or ducting infrastructure

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Object-affected harmful factors

If VIGVs are positioned closer to ESS vanes to maximize shielding effect, then ice accumulation is reduced, but manufacturing precision requirements increase to maintain optimal geometric ratios

Engineering Contradiction:

Improveice accumulation on VIGVsVSAvoidpositioning precision of VIGVs relative to ESS

Core Design Contradiction:

Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The invention defines specific geometric parameter ranges (axial distance L, radial distance ΔR, angle α) that create effective shielding zones. By establishing these parameter boundaries, the design provides manufacturing flexibility while ensuring the VIGVs remain within protective flow regions. The parameter ranges accommodate normal manufacturing tolerances while maintaining the aerodynamic shielding effect

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention creates localized protective flow regions with specific aerodynamic characteristics behind the ESS vanes. By positioning VIGVs within these locally optimized zones defined by the geometric parameters, the system achieves ice protection through localized flow manipulation rather than requiring precision across the entire engine assembly

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 effectively reduces ice accumulation on VIGVs, maintaining engine efficiency and performance without the need for additional hardware, thus addressing the issues of weight and complexity in existing anti-icing systems.

Implementation Method 1

Methodology Applied

Scientific EffectAerodynamic shielding:

Data Source

PatentUS11920499B2Gas turbine engine with improved VIGV shielding

Publication Date: 2024.03.05 ROLLS ROYCE PLC

AI summary

A gas turbine engine includes: a fan rotating about an engine main axis; a core duct; an engine core; an Engine Section Stator (ESS) including a plurality of ESS vanes and arranged in the core duct downstream of the fan; and a plurality of variable inlet guide vanes (VIGV) adapted to rotate about a pivot axis and arranged in the core duct downstream of the ESS. The VIGV vanes are arranged angularly rotated with respect to the ESS vanes such that the VIGVs are shielded by the ESS, thereby protecting the VIGVs from icing and from ice shedding from the ESS vanes.