Mixed-Flow Thrust Reverser With Independent Throat and Exit Control

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Solution Overview

Problem

Existing mixed flow exhaust nozzles in turbofan engines lack the ability to independently control the nozzle throat and exit areas, limiting the effectiveness of thrust reversal during aircraft landing and takeoff.

Innovation Solution

An articulating exhaust nozzle system with independently controllable nozzle throat and exit areas, utilizing multiple actuators and articulating panels to pivot and adjust these areas independently, allowing for optimized thrust reversal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a conventional fixed-area nozzle is used, then the structure is simple, but the thrust reversal effectiveness is limited

Engineering Contradiction:

Improvethrust reversal effectivenessVSAvoidnozzle structure complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The nozzle transitions from a fixed structure to a dynamic system with articulating panels that can pivot to change the nozzle throat and exit areas independently. This allows the nozzle to adapt its geometry during thrust reversal operations to optimize performance while managing the added mechanical complexity through controlled articulation mechanisms

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The nozzle is divided into multiple articulating panels (inner and outer panels) that can move independently relative to each other. This segmentation enables separate control of the nozzle throat area and exit area, allowing optimization of thrust reversal effectiveness without requiring a completely complex redesign of the entire nozzle system

Inventive Principle:

Principle #1Segmentation

2Force

If the nozzle throat area is increased to improve thrust reversal, then the reverse thrust is enhanced, but the aircraft deceleration performance deteriorates

Engineering Contradiction:

Improvereverse thrustVSAvoidaircraft deceleration

Core Design Contradiction:

ForceVSSpeed

Solution Approach 1:

The system changes the geometric parameters of the nozzle by independently varying the throat area and exit area through panel articulation. By coordinating the movement of inner and outer panels, the system can optimize the balance between generating sufficient reverse thrust and maintaining effective airflow for aircraft deceleration, rather than using a fixed area that compromises one parameter for the other

Inventive Principle:

Principle #35Parameter changes

3Productivity

If multiple articulating panels are added to enable independent area control, then the thrust reversal is optimized, but the manufacturing complexity increases

Engineering Contradiction:

Improvethrust reversal efficiencyVSAvoidnozzle manufacturing complexity

Core Design Contradiction:

ProductivityVSEase of manufacture

Solution Approach 1:

The articulating panels serve multiple functions: they control the nozzle throat area, control the exit area, and maintain structural integrity during thrust reversal. This multi-functionality reduces the need for separate specialized components, thereby managing manufacturing complexity while achieving optimized thrust reversal efficiency

Inventive Principle:

Principle #6Universality (Multi-functionality)

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

Enhances thrust reversal efficiency by independently varying nozzle throat and exit areas, improving aircraft deceleration during landing and takeoff, and maintaining aerodynamic continuity.

Implementation Method 1

independently controllable nozzle throat and exit areas, utilizing multiple actuators and articulating panels to pivot and adjust these areas independently

Methodology Applied

Scientific EffectFluid flow control:

Implementation Method 2

The inner thrust reverser door and the outer thrust reverser door are configured to redirect exhaust gasses to generate reverse thrust to an aircraft

Methodology Applied

Scientific EffectMomentum reversal: Conservation of Momentum

Data Source

PatentUS12497932B2Mixed flow exhaust thrust reverser with area control nozzle systems and methods

Publication Date: 2025.12.16 ROHR INC

AI summary

A thrust reverser includes an outer articulating panel and an inner articulating panel. The outer articulating panel includes an outer thrust reverser door pivotally coupled to the outer articulating panel. The outer thrust reverser door is movable between an outer door stowed position and an outer door deployed position with respect to the outer articulating panel. The inner articulating panel includes an inner thrust reverser door pivotally coupled to the inner articulating panel. The inner thrust reverser door is movable between an inner door stowed position and an inner door deployed position with respect to the inner articulating panel. The inner thrust reverser door and the outer thrust reverser door are configured to redirect exhaust gasses to generate reverse thrust to an aircraft when the thrust reverser doors are in the deployed positions.