Variable Area Nozzle Thrust Reverser With Movable Panels

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Solution Overview

Problem

Existing variable area nozzle assemblies for aircraft gas turbine engines do not adequately address the need to vary the nozzle area to ensure efficient operation across a range of flight conditions, including subsonic, transonic, and supersonic speeds.

Innovation Solution

A variable area nozzle assembly with movable panels and thrust reverser doors that allow for adjustable cross-sectional areas, controlled by actuators, to optimize exhaust gas flow and positioning for different flight conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a fixed area nozzle is used, then the structure is simple, but the engine cannot efficiently operate across a range of flight conditions (subsonic, transonic, and supersonic speeds)

Engineering Contradiction:
Improveadaptability to different flight conditionsVSAvoidnozzle structure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The nozzle is divided into multiple movable panels (first movable panel, second movable panel, third movable panel, fourth movable panel) that can independently adjust their positions. Each panel is controlled by separate actuators, allowing the nozzle area to be segmented and adjusted in steps to match different flight conditions, thereby improving adaptability while managing structural complexity through modular design

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The nozzle transitions from a fixed structure to a dynamic one with movable panels that can change position based on flight conditions. The actuators enable continuous or discrete adjustment of the nozzle cross-sectional area, allowing the engine to optimize performance across subsonic, transonic, and supersonic regimes by dynamically adapting the exhaust flow area

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If movable panels and thrust reverser doors are added to vary nozzle area, then adaptability to different flight conditions improves, but device complexity increases

Engineering Contradiction:
Improvenozzle area adjustabilityVSAvoidactuator control system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The movable panels serve multiple functions: they act as both nozzle area control surfaces for optimizing exhaust flow during normal operation and as thrust reverser doors for deceleration. This multi-functionality reduces the need for separate components, thereby managing complexity while achieving both adaptability and thrust reversal capability

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The thrust reverser function is merged with the movable nozzle panels. The same panels that adjust the nozzle area for different flight conditions also serve as the thrust reverser doors when positioned to block and redirect exhaust flow forward. This integration combines multiple functions into a single structural element, reducing overall system complexity

Inventive Principle:
Principle #5Merging (Combining)

3Ease of operation

If conventional exhaust nozzle designs are used, then manufacturing is straightforward, but thrust management and weight distribution are suboptimal

Engineering Contradiction:
Improvethrust management capabilityVSAvoidnozzle assembly manufacturing
Core Design Contradiction:
Ease of operationVSEase of manufacture

Solution Approach 1:

The nozzle is segmented into multiple movable panels rather than a single monolithic structure. This segmentation allows for improved thrust management through precise control of exhaust flow direction and area, while also simplifying manufacturing by enabling each panel to be produced and tested independently before assembly, thereby balancing operational capability with manufacturability

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4242444B1Thrust reverser for variable area nozzle
Publication Date: 2025.09.24 ROHR INC
  • EP4242444B1 patent drawingFigure 1
  • EP4242444B1 patent drawingFigure 2
  • EP4242444B1 patent drawingFigure 3

AI summary

A variable area nozzle assembly (46) for a gas turbine engine includes a fixed structure (48) surrounding an exhaust duct extending along a nozzle centerline. The fixed structure (48) further includes a first lateral side (62) and a second lateral side (64) opposite the first lateral side (62). The variable area nozzle assembly (46) further includes a nozzle (54). The nozzle (54) includes a nozzle outlet (119) including a nozzle outlet cross-sectional area. The variable area nozzle assembly (46) further includes a thrust reverser system (132) including a first thrust reverser door (134) and a second thrust reverser door (136). The first thrust reverser door (134) is pivotably mounted to the fixed structure (48) at the first lateral side (62). The second thrust reverser door (136) is pivotably mounted to the fixed structure (48) at the second lateral side (64). The first thrust reverser door (134) and the second thrust reverser door (136) define a portion of the nozzle outlet (119) of the nozzle.