Gas Turbine Exhaust Nozzle Axial Strut Actuation

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Solution Overview

Problem

Existing variable area exhaust nozzles for gas turbine engines require radial space for strut adjustment mechanisms, increasing overall wall thickness and efficiency concerns.

Innovation Solution

Integration of sliding elements with interaction structures and actuators within the thrust reverser unit, allowing axial movement of struts without increasing radial space, using a worm and rack drive or linear actuator mechanisms.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If traditional adjustment mechanisms are used to move the centerbody axially, then the nozzle can achieve variable area functionality, but the radial space required increases the overall wall thickness

Engineering Contradiction:

Improvevariable area functionalityVSAvoidwall thickness

Core Design Contradiction:

Adaptability or versatilityVSLength of stationary object

Solution Approach 1:

The patent merges the actuator with the thrust reverser unit structure, integrating the adjustment mechanism into the existing nozzle wall components. The actuator is positioned within the thrust reverser unit and uses its structural elements (beams, pivot doors) as part of the actuation system, thereby eliminating the need for separate radial adjustment mechanisms and avoiding increased wall thickness.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent transitions from radial adjustment mechanisms to axial movement within the thrust reverser unit. The centerbody is moved axially by engaging with the thrust reverser unit's structural components, utilizing the axial space already present in the nozzle design rather than requiring additional radial space.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Strength

If struts are connected to the outer nozzle wall, then structural support is provided, but radial space is consumed by adjustment mechanisms

Engineering Contradiction:

Improvestructural supportVSAvoidradial space

Core Design Contradiction:

StrengthVSArea of stationary object

Solution Approach 1:

The patent combines the strut connection function with the thrust reverser unit's structural beams. The struts connect to the beams that form part of the thrust reverser unit, merging the support function with the actuation structure. This integration allows axial movement of the centerbody while maintaining structural support without consuming additional radial space.

Inventive Principle:

Principle #5Merging (Combining)

3Ease of operation

If actuators are positioned externally to adjust struts, then axial movement is achieved, but the nozzle structure becomes more complex

Engineering Contradiction:

Improveaxial movement capabilityVSAvoidnozzle structure

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The patent integrates the actuator into the thrust reverser unit's internal structure, positioning it within the existing beam and pivot door assembly. This merging of the actuator with the thrust reverser unit eliminates the need for external actuation mechanisms, simplifying the overall nozzle structure while maintaining axial movement capability.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The thrust reverser unit's structural components (beams, pivot doors) serve dual functions: providing structural support for the thrust reverser mechanism and serving as the actuation system for moving the centerbody. This multi-functionality reduces the number of separate components needed, simplifying the nozzle structure.

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

Enables effective axial movement of the centerbody relative to the outer nozzle wall, optimizing radial space usage and enhancing the nozzle's variable area functionality while maintaining structural integrity and reducing air leakage.

Implementation Method 1

The actuator may comprise a worm screw that interacts with the toothing of the sliding element. In such case, the actuator and the toothing of the sliding element form a worm and rack drive.

Methodology Applied

Scientific EffectWorm and rack drive: Rack and Pinion

Implementation Method 2

For allowing axial relative movement between the struts and the outer nozzle wall, each strut comprises a sliding element extending radially from the radial outer end of the strut, wherein the sliding element is arranged in a receiving slot that extends in the axial direction in the nozzle wall.

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentUS11326553B2Exhaust nozzle of a gas turbine engine

Publication Date: 2022.05.10 ROLLS ROYCE DEUT LTD & CO KG

AI summary

Aspects of the disclosure regard an exhaust nozzle of a gas turbine engine which includes an outer nozzle wall, a flow channel, a centerbody arranged in the flow channel, at least two struts connecting the centerbody to the nozzle wall, a thrust reverser unit, and a plurality of actuators, wherein each actuator is associated with a strut for displacing the strut in the axial direction. The struts are connected to a structure of the outer nozzle wall that forms part of the thrust reverser unit. For allowing axial relative movement between the struts and the outer nozzle wall, each strut includes a sliding element extending radially from the radial outer end of the strut, wherein the sliding element is arranged in a receiving slot that extends in the axial direction in the nozzle wall. It is provided that the sliding element comprises an interaction structure that interacts with one of the actuators for effecting relative axial movement between the strut and the nozzle wall.