Inflatable Jet Nozzle Area Control for Lighter Turbine Engines

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Solution Overview

Problem

Existing jet nozzle effective area adjustment mechanisms for aircraft gas turbine engines are inefficient and add weight to the engine, with existing systems, the technical problem is that existing jet nozzle effective area adjustment mechanisms are inefficient and add size, weight, and expense to the engine.

Innovation Solution

Aircraft gas turbine engines with an outer bypass section wall and a jet nozzle featuring an inflatable diaphragm, controlled by a fluid pressure sensor, inlet valve, and release valve to adjust the effective area without mechanical actuators, segmented panels, or pivot joints.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If existing jet nozzle effective area adjustment mechanisms are used, then the effective area can be adjusted, but size, weight, and expense increase

Engineering Contradiction:
Improveeffective area adjustmentVSAvoidengine weight
Core Design Contradiction:
Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

The patent replaces traditional mechanical actuators, segmented panels, and pivot joints with an inflatable diaphragm system. The diaphragm is inflated or deflated using fluid pressure to change the jet nozzle effective area, eliminating complex mechanical moving parts and significantly reducing weight while maintaining adjustability

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention uses fluid pressure (pneumatics) to control the inflatable diaphragm. By introducing pressurized fluid into the diaphragm, the effective area of the jet nozzle is reduced; by releasing fluid, the effective area increases. This pneumatic control system replaces heavy mechanical actuation mechanisms

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Adaptability or versatility

If existing jet nozzle effective area adjustment mechanisms are used, then the effective area can be adjusted, but device complexity increases

Engineering Contradiction:
Improveeffective area adjustmentVSAvoidmechanical complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent eliminates multiple mechanical actuators, segmented panels, and pivot joints by using a single inflatable diaphragm controlled by fluid pressure. This substitution dramatically simplifies the mechanical complexity while preserving the ability to adjust the effective area

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention uses an inflatable diaphragm (a flexible membrane) to control the jet nozzle effective area. This flexible shell approach replaces rigid mechanical components with a simple, adaptable membrane that can change shape based on fluid pressure, reducing overall device complexity

Inventive Principle:
Principle #30Flexible shells and thin films

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

The solution provides a lightweight and efficient mechanism to adjust the effective area of the jet nozzle by controlling fluid pressure within the diaphragm, reducing size and mechanical complexity.

Implementation Method 1

The at least one inflatable diaphragm may be configured to expand into the jet nozzle when the fluid pressure within the at least one inflatable diaphragm is increased such that an effective area of the jet nozzle is reduced

Methodology Applied
Scientific EffectFluid pressure: Pressure Increase

Data Source

PatentEP4707573A1Jet nozzle effective area control system for gas turbine engine
Publication Date: 2026.03.11 PRATT & WHITNEY CANADA CORP
  • EP4707573A1 patent drawingFigure 1A
  • EP4707573A1 patent drawingFigure 1B
  • EP4707573A1 patent drawingFigure 1C

AI summary

A gas turbine engine for an aircraft includes an outer bypass section wall, and a jet nozzle including at least one inflatable diaphragm (112). The at least one inflatable diaphragm (112) is disposed along the outer bypass section wall. The gas turbine engine also includes a fluid pressure sensor (120) configured to measure a fluid pressure within the at least one inflatable diaphragm (112), an inlet valve (122) configured to control a pressurized flow of a fluid into the at least one inflatable diaphragm (112) in response to a command from a controller (104), and a release valve (124) configured to control a release of the fluid from within the at least one inflatable diaphragm (112) in response to a command from the controller (104).