Variable Area Nozzle Sleeve Actuation Under Radial Loads
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Solution Overview
Problem
Existing variable area nozzles for aircraft engines require improvements in terms of structural support and control mechanisms to effectively manage radial loads and adjust the flow area efficiently.
Innovation Solution
A variable area nozzle design featuring a nozzle inner and outer structure, an actuation system with a carriage and actuator, and a flowpath, which allows for axial translation of the nozzle sleeve to adjust the flow area by using a carriage that supports radial loads and is coupled to a linear actuator for precise control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a variable area nozzle is used to adjust flow area, then thrust management efficiency is improved, but structural complexity increases due to additional actuation systems
Solution Approach 1:
The nozzle is divided into separate functional components: a nozzle body, a movable nozzle sleeve, struts for load bearing, and an actuation system. This segmentation allows each component to be optimized independently while working together to achieve efficient thrust management through the movable sleeve that adjusts the flow area.
Solution Approach 2:
Struts are introduced as intermediary elements between the nozzle sleeve and nozzle body. These struts serve as mediators that transfer radial loads from the movable sleeve to the stationary nozzle body, enabling the actuation system to control the sleeve position without directly bearing the radial forces, thus simplifying the overall actuation system design.
2Productivity
If the nozzle sleeve is made movable to adjust flow area, then operational performance is improved, but radial load management becomes more difficult
Solution Approach 1:
Struts are introduced as intermediary elements between the nozzle sleeve and nozzle body. These struts serve as mediators that transfer radial loads from the movable sleeve to the stationary nozzle body, enabling the actuation system to control the sleeve position without directly bearing the radial forces, thus simplifying the overall actuation system design.
Solution Approach 2:
The nozzle sleeve is designed as a dynamic component that can move axially to adjust the flow area while the struts dynamically transfer radial loads during operation. This dynamic design allows the nozzle to adapt its geometry for optimal performance while maintaining structural integrity through automatic load distribution via the struts.
Data Source
AI summary
A variable area nozzle for an aircraft engine includes a nozzle inner structure, a nozzle outer structure, an actuation system and a flowpath. The nozzle inner structure includes a nozzle wall and a nozzle sleeve. The nozzle wall includes a plurality of slots arranged circumferentially about the axis. Each of the slots projects radially through the nozzle wall. The nozzle sleeve axially overlaps and circumscribes the nozzle wall. The actuation system includes a carriage and an actuator. The carriage includes a hub and a plurality of struts arranged circumferentially about and connected to the hub. Each of the struts projects radially through a respective slot where the nozzle sleeve is attached to the carriage at an outer end of the carriage. The actuator is disposed radially within the inner nozzle wall and is coupled to the hub. The actuation system moves the nozzle sleeve axially along the nozzle wall.