Fan Variable Area Nozzle Drive Ring Actuation

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Solution Overview

Problem

Conventional gas turbine engines have fixed geometry fan nozzles that compromise performance across different flight conditions, and existing variable area nozzles are heavy and lack thrust vectoring capability.

Innovation Solution

A fan variable area nozzle (FVAN) with a flap assembly and actuator system that axially and radially translates a drive ring to symmetrically and asymmetrically adjust the fan nozzle exit area, enabling thrust vectoring and optimizing thrust and fuel efficiency across flight regimes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional fixed geometry fan nozzles are used, then the engine structure is simple, but the fuel efficiency and thrust performance are compromised across different flight conditions

Engineering Contradiction:

Improvefuel efficiency across flight conditionsVSAvoidnozzle structure complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements a variable geometry nozzle system where the nozzle exit area can dynamically change between different flight conditions (take-off, cruise, landing). The nozzle area is adjusted using a drive ring mechanism that translates radially to modify the nozzle cross-sectional area, allowing the engine to optimize performance for each flight regime rather than relying on a fixed geometry compromise.

Inventive Principle:

Principle #15Dynamics

2Adaptability or versatility

If existing fan variable area nozzles are implemented, then the nozzle area can be adjusted for different flight conditions, but the overall engine weight increases significantly

Engineering Contradiction:

Improvenozzle area adjustment capabilityVSAvoidengine weight

Core Design Contradiction:

Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

The nozzle is divided into multiple independent segments or panels that can be individually adjusted. The drive ring mechanism is segmented into discrete actuators that control different sections of the nozzle, allowing for distributed weight distribution and more efficient use of materials. This segmentation enables the nozzle to achieve variable area capability without requiring a completely heavy, monolithic adjustable structure.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent replaces traditional heavy mechanical linkage systems with a more efficient drive ring actuation mechanism. The drive ring translates radially in response to actuator signals, directly controlling the nozzle area without requiring complex intermediate linkages. This substitution of the mechanical control system reduces overall weight while maintaining full variable area capability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Adaptability or versatility

If conventional fixed direction fan nozzles are used, then the nozzle structure is simple, but the thrust vectoring capability is lost

Engineering Contradiction:

Improvethrust vectoring capabilityVSAvoidnozzle control system complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The drive ring mechanism serves multiple functions simultaneously: it controls the nozzle exit area for fuel efficiency optimization and provides thrust vectoring capability for maneuverability enhancement. By integrating both area control and direction control into a single actuation system, the patent achieves multi-functionality without proportionally increasing complexity. The same radial translation mechanism that adjusts area also enables directional control when offset from the engine axis.

Inventive Principle:

Principle #6Universality (Multi-functionality)

4Adaptability or versatility

If complex mechanisms are used for fan variable area nozzles, then the nozzle area can be varied, but the fuel efficiency gains are negated by increased weight

Engineering Contradiction:

Improvenozzle area variationVSAvoidfuel efficiency

Core Design Contradiction:

Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The patent replaces complex traditional mechanical variable area mechanisms with a simplified drive ring actuation system. The drive ring translates radially in response to actuator commands, directly modifying the nozzle area without requiring complex linkages, levers, or mechanical advantage systems. This mechanical substitution reduces the weight of the variable area mechanism, ensuring that the fuel efficiency gains from optimized nozzle area control are not negated by increased mechanical system weight.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS8316646B2Fan variable area nozzle for a gas turbine engine fan nacelle with drive ring actuation system

Publication Date: 2012.11.27 RTX CORP

AI summary

A fan variable area nozzle (FVAN) includes a flap assembly which varies a fan nozzle exit area. The flap assembly generally includes a multiple of flaps, flap linkages and an actuator system. The actuator system radially and axially translates a drive ring relative an engine centerline axis. A slot within the drive ring receives the flap linkages to asymmetrically and symmetrically vary the fan nozzle exit area in response to movement of the drive ring.