Fan Variable Area Nozzle Position Measurement

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Solution Overview

Problem

Conventional gas turbine engines with fixed geometry fan nozzles face challenges in optimizing performance across different flight conditions, particularly due to the complexity and weight of mechanisms used in variable area nozzles for determining position, especially in asymmetric operations.

Innovation Solution

A positional measurement system that remotely senses the position of fan variable area nozzle flaps using optical, microwave, or radio signals, allowing for lightweight and effective position determination, enabling asymmetrical thrust vectoring operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional linkage mechanisms with linear variable displacement transducers are used to determine fan variable area nozzle position, then position measurement reliability is improved, but device complexity and weight increase significantly

Engineering Contradiction:

Improveposition measurement reliabilityVSAvoidlinkage mechanism complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical linkage system with a non-contact optical measurement system. Optical sensors (such as laser displacement sensors or optical encoders) measure the nozzle position by detecting the position of a reflective marker or the direct optical path length, eliminating the need for physical linkages and mechanical transducers. This substitution maintains measurement reliability while dramatically reducing mechanical complexity and weight.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces an optical field as an intermediary between the measurement system and the nozzle. Optical sensors detect position through electromagnetic radiation (light) rather than direct mechanical contact. This intermediary approach allows remote, non-contact measurement, avoiding the mechanical coupling complexity while maintaining accurate position determination.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If multiple sets of linkages are used for asymmetric operation capability, then adaptability to different flight conditions is improved, but device complexity and weight increase

Engineering Contradiction:

Improveasymmetric operation capabilityVSAvoidlinkage system complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent replaces multiple mechanical linkage sets with a single optical measurement system that can detect asymmetric nozzle positions. The optical sensors measure the actual position of each nozzle sector independently, allowing the control system to determine and respond to asymmetric conditions without requiring separate mechanical linkages for each sector. This maintains adaptability while reducing overall system complexity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent employs a universal optical measurement system that serves multiple functions: it measures position for symmetric operation, detects asymmetric conditions, and provides data for thrust vectoring control. This single multi-functional system replaces what would traditionally require multiple specialized mechanical linkage sets, reducing complexity while maintaining full operational adaptability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Device complexity

If fixed geometry fan nozzles are used, then device complexity is reduced, but adaptability to different flight conditions deteriorates

Engineering Contradiction:

Improvenozzle structure complexityVSAvoidperformance optimization across flight conditions

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent implements a dynamically adjustable fan nozzle area while maintaining relatively simple overall structure. The nozzle can vary its effective area through controlled movement of nozzle sectors or flaps actuated by positioners, allowing adaptation to different flight conditions (take-off, landing, cruise) without requiring complex fixed-geometry arrangements. The dynamic capability provides performance optimization across regimes while keeping structural complexity manageable.

Inventive Principle:

Principle #15Dynamics

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 solution provides a lightweight and efficient means to determine the position of fan variable area nozzles, optimizing engine performance across various flight conditions by enabling precise control of fan nozzle exit areas, thereby enhancing thrust efficiency and fuel economy.

Implementation Method 1

a sensor system located within the core nacelle to remotely measure the position of each flap or set of flaps through a transmitted signal such as an optical, microwave, radio wave, laser or other signal which reflects off of the flap or set of flaps

Methodology Applied

Scientific EffectReflection: Reflection

Data Source

PatentUS8235325B2Fan variable area nozzle positional measurement system

Publication Date: 2012.08.07 RTX CORP

AI summary

A positional measurement system for a fan variable area nozzle (FVAN) remotely determines the position of each flap or set of flaps relative a core nacelle. The positional measurement system includes a sensor system with a multiple of transceivers located within the core nacelle to remotely measure the position of each flap or set of flaps without the heretofore necessity of moving measurement components.