Variable Area Nozzle Panels for Adaptive Gas Turbine Thrust

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Solution Overview

Problem

Existing variable area nozzle assemblies for aircraft gas turbine engines do not adequately address the need for efficient operation across a range of flight conditions, particularly in varying exhaust gas speeds.

Innovation Solution

A variable area nozzle assembly with pivotable panels and actuation systems that allow for precise control of the cross-sectional area of the nozzle, including convergent-divergent configurations, to optimize exhaust gas flow and thrust vectoring.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a variable area nozzle assembly is used to accommodate different flight conditions, then the adaptability and efficiency of the gas turbine engine improve, but the device complexity increases due to multiple movable panels and actuation systems

Engineering Contradiction:
Improveadaptability to different flight conditionsVSAvoidcomplexity of nozzle assembly
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The nozzle assembly is divided into multiple movable panels (first movable panel, second movable panel, third movable panel, fourth movable panel) that can independently pivot to adjust the cross-sectional area. Each panel is equipped with its own actuation system, allowing segmented control of different sections of the nozzle to achieve various area configurations for different flight conditions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The nozzle assembly transitions from a static structure to a dynamic one with panels that can pivot and actuate in real-time. The movable panels are designed to rotate about pivot axes, enabling continuous adjustment of the nozzle area during operation to adapt to varying exhaust gas speeds and flight conditions.

Inventive Principle:
Principle #15Dynamics

2Manufacturing precision

If multiple movable panels with independent actuation systems are implemented, then the precision of cross-sectional area control improves, but the manufacturing complexity and cost increase

Engineering Contradiction:
Improveprecision of area controlVSAvoidease of manufacture
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The precision control is achieved by segmenting the nozzle into multiple independently actuated panels. Each panel can be controlled to specific positions, allowing fine-grained adjustment of the overall cross-sectional area. The segmentation enables precise control of each section while maintaining manufacturing feasibility through modular construction.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The actuation systems are designed to control the pivot angle of each panel, changing the geometric parameters of the nozzle cross-section. By adjusting the angular position of individual panels, the system achieves precise area control through parameter variation rather than requiring complex mechanical linkages.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If the nozzle area is varied to optimize exhaust flow, then the thrust performance improves, but the structural complexity of the actuation system increases

Engineering Contradiction:
Improvethrust performanceVSAvoidcomplexity of actuation system
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The actuation system employs dynamic pivot mechanisms that allow panels to rotate and adjust the nozzle area in real-time during engine operation. This dynamic capability enables optimization of thrust performance across different flight conditions without requiring a completely reconfigurable structure.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The actuation system controls the geometric parameters of the nozzle by varying the pivot angles of individual panels. This parameter-based control approach allows precise adjustment of the exhaust flow area to optimize thrust, using simpler angular actuation rather than complex linear positioning mechanisms.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4242445B1Variable area nozzle assembly and method for operating a variable area nozzle assembly
Publication Date: 2025.09.10 ROHR INC
  • EP4242445B1 patent drawingFigure 1
  • EP4242445B1 patent drawingFigure 2
  • EP4242445B1 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 (50) extending along a nozzle centerline (52). The fixed structure (48) includes an upper side and a lower side opposite the upper side (58). The variable area nozzle assembly (46) further includes a nozzle disposed about the nozzle centerline (52). The nozzle (54) includes a nozzle throat cross-sectional area and a nozzle outlet cross-sectional area downstream of the nozzle throat cross-sectional area. The nozzle includes an upper panel (74) and a lower panel (76). The upper panel (74) includes an upper downstream end (80) and the lower panel (76) including a lower downstream end (80). The upper downstream end (80) and the lower downstream end (80) define a portion of the nozzle throat cross-sectional area (86). The variable area nozzle assembly (46) further includes a nozzle actuation system (130) including an upper shaft (144) connected to the upper panel (76) and a lower shaft (162) connected to the lower panel (76).