Jet Nozzle Area Control Using Inflatable Diaphragms

Solution Overview

Problem

Existing jet nozzle effective area adjustment mechanisms in gas turbine engines are bulky, heavy, and expensive due to the use of multiple actuators, segmented panels, and mechanical arms, which increase the size and weight of the engine.

Innovation Solution

The implementation of inflatable diaphragms and hinged panels in the jet nozzle, controlled by a fluid pressure system, to adjust the effective area without the need for additional actuators, reducing mechanical complexity and weight.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple actuators, segmented panels, and mechanical arms are used to adjust jet nozzle effective area, then the jet nozzle effective area can be adjusted to enhance engine performance, but the size, weight, and expense of the engine increase

Engineering Contradiction:

Improvejet nozzle effective area adjustmentVSAvoidengine weight

Core Design Contradiction:

Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

The patent replaces complex mechanical actuation systems with a pneumatic system. Inflatable diaphragms use pressurized air to expand and contract, thereby adjusting the jet nozzle effective area. This eliminates the need for heavy mechanical actuators, segmented panels, and mechanical arms, significantly reducing engine weight while maintaining adjustment capability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention employs pneumatic pressure to control the diaphragm expansion and contraction. By regulating air pressure within the diaphragm structure, the jet nozzle effective area is dynamically adjusted. This pneumatic approach replaces traditional mechanical actuation, reducing complexity and weight.

Inventive Principle:

Principle #29Pneumatics and hydraulics

2Adaptability or versatility

If multiple actuators, segmented panels, and mechanical arms are used to adjust jet nozzle effective area, then the jet nozzle effective area can be adjusted to enhance engine performance, but the device complexity increases

Engineering Contradiction:

Improvejet nozzle effective area adjustmentVSAvoidmechanical complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical actuation systems with a pneumatic system. Inflatable diaphragms use pressurized air to expand and contract, thereby adjusting the jet nozzle effective area. This eliminates the need for heavy mechanical actuators, segmented panels, and mechanical arms, significantly reducing engine weight while maintaining adjustment capability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention adjusts the jet nozzle effective area by changing the physical state of the diaphragm from deflated to inflated. By controlling air pressure parameters, the diaphragm transitions between states, dynamically adjusting the nozzle area without complex mechanical transformations.

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If multiple actuators, segmented panels, and mechanical arms are used to adjust jet nozzle effective area, then the jet nozzle effective area can be adjusted to enhance engine performance, but the expense increases

Engineering Contradiction:

Improvejet nozzle effective area adjustmentVSAvoidmanufacturing cost

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent replaces complex mechanical actuation systems with a pneumatic system. Inflatable diaphragms use pressurized air to expand and contract, thereby adjusting the jet nozzle effective area. This eliminates the need for heavy mechanical actuators, segmented panels, and mechanical arms, significantly reducing engine weight while maintaining adjustment capability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 cost-effective mechanism for adjusting the jet nozzle effective area, enhancing engine performance and efficiency by modulating the diaphragm inflation during various operating conditions.

Implementation Method 1

increasing a fluid pressure in at least one inflatable diaphragm disposed at the jet nozzle

Methodology Applied

Scientific EffectFluid pressure: Pressure Increase

Implementation Method 2

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 the effective area of the jet nozzle is reduced

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 3

decreasing a fluid pressure in at least one inflatable diaphragm disposed at the jet nozzle

Methodology Applied

Scientific EffectFluid pressure: Pressure Increase

Implementation Method 4

The at least one inflatable diaphragm may be configured to recede from the jet nozzle when the fluid pressure within the at least one inflatable diaphragm is decreased such that the effective area of the jet nozzle is increased

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS20260055744A1Jet nozzle effective area control system for gas turbine engine

Publication Date: 2026.02.26 PRATT & WHITNEY CANADA CORP

AI summary

An aircraft gas turbine engine includes a fan that in operation moves air through both a core airflow path and a bypass airflow path of the gas turbine engine. The core airflow path and the bypass airflow path converge at a jet nozzle of the gas turbine engine. A method of controlling the gas turbine engine includes detecting, at a controller of the gas turbine engine, a cruise operating condition of the gas turbine engine, and in response to detecting the cruise operating condition, operating a mechanism of the gas turbine engine to decrease an effective area of the jet nozzle.