Variable Flow Pylon Nozzle for Gas Turbine Thrust Management

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Solution Overview

Problem

Conventional gas turbine engines with fixed geometry fan nozzles are inefficient as they compromise between take-off and cruise conditions, and existing fan variable area nozzles are heavy due to complex mechanisms, negating fuel efficiency gains.

Innovation Solution

A pylon structure with a variable area flow system that adjusts the bypass flow area by opening and closing additional flow areas between the pylon intake and exhaust, allowing for a 20% change in fan exit nozzle area to optimize thrust across different flight conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If fixed geometry fan nozzles are used, then the engine structure is simple, but the engine efficiency is compromised between take-off and cruise conditions

Engineering Contradiction:

Improveengine efficiencyVSAvoidnozzle geometry

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies dynamics by making the nozzle geometry variable rather than fixed. The bifurcation structure includes movable elements that can change the flow area dynamically to match different flight conditions (take-off, cruise, landing), allowing the engine to optimize efficiency across all operating regimes rather than being compromised by a single fixed geometry design

Inventive Principle:

Principle #15Dynamics

2Adaptability or versatility

If existing fan variable area nozzles are implemented, then the fan exit nozzle diameter can be varied, but the overall engine weight increases due to complex mechanisms

Engineering Contradiction:

Improvefan exit nozzle diameter variationVSAvoidengine weight

Core Design Contradiction:

Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

The patent segments the flow control function by separating the variable area mechanism into the bifurcation structure rather than using a single complex variable area nozzle. This segmentation allows for simpler, lighter individual components that collectively achieve the desired fan exit area variation, reducing overall engine weight while maintaining adaptability

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The bifurcation structure acts as an intermediary element that mediates between the fan and the exhaust. By placing the variable area flow system in the bifurcation rather than directly in the fan nozzle, the patent achieves fan exit area variation with reduced mechanical complexity and weight compared to traditional variable area nozzle designs

Inventive Principle:

Principle #24Intermediary (Mediator)

3Use of energy by moving object

If fan variable area nozzles are used, then fuel efficiency is improved, but the increased engine weight negates the fuel efficiency gains

Engineering Contradiction:

Improvefuel efficiencyVSAvoidengine weight

Core Design Contradiction:

Use of energy by moving objectVSWeight of moving object

Solution Approach 1:

The patent changes the physical parameters of the flow system by varying the bifurcation flow area to control the fan exit nozzle area. This parameter change approach allows for efficient thrust management across different flight conditions with a lighter weight system, as the variable area is achieved through geometric adjustment in the bifurcation rather than through heavy mechanical nozzle mechanisms

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS8418471B2Gas turbine engine having variable flow through a bifurcation having an intake with multiple louvers

Publication Date: 2013.04.16 RTX CORP

AI summary

A turbofan engine pylon structure has a fan variable area nozzle defined by a variable area flow system between a pylon intake and a pylon exhaust to selectively adjust a bypass flow through the pylon structure. The variable area flow system changes the physical area and geometry of a pylon nozzle exit area to manipulate the bypass flow by opening and closing an additional flow area of the variable area flow system.