Turbojet Nacelle Panel Actuation Reducing Axial Forces
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Solution Overview
Problem
Existing nacelle designs for aircraft turbojet engines face issues with axial forces generated by actuator systems for variable nozzle panels, leading to structural deformations and inefficiencies, particularly when using segregated or pooled actuation systems.
Innovation Solution
The nacelle incorporates a panel actuation system with lateral rods connected to the panel and the external cowling, pivotally mounted around multiple axes, and a linear actuator that moves the lateral rod to pivot the panel, distributing forces circumferentially and reducing axial loads, along with a movement return device using a yoke and spider mechanism to enhance aerodynamic performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a conventional actuation system with actuators parallel to the nacelle longitudinal axis is used to rotate nozzle panels, then the nozzle panels can be actuated effectively, but detrimental axial forces are generated that cause scooping and deformation of the nacelle structure
Solution Approach 1:
The patent changes the orientation of the actuator from parallel to the longitudinal axis (one dimension) to perpendicular to the longitudinal axis (another dimension). This dimensional change redirects the force vector from axial to radial direction, eliminating the harmful scooping effect while maintaining panel actuation capability
Solution Approach 2:
The actuation system is segmented into independent components: the actuator, the lateral rod, and the panel rotation mechanism. This segmentation allows the actuator to apply force laterally to the rod, which then converts it to rotational motion of the panel, separating the force application direction from the panel rotation axis
2Adaptability or versatility
If segregated actuation systems are used for nozzle panels and thrust reverser cowl, then independent actuation is achieved, but device complexity increases
Solution Approach 1:
The actuation system design with laterally-oriented actuators and lateral rods creates a universal mechanism that can be applied to both nozzle panel actuation and thrust reverser cowl actuation. This multi-functional approach allows a single actuator type to control multiple components independently, reducing overall system complexity while maintaining adaptability
Data Source
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AI summary
The invention relates to a pod for a turbojet engine, which comprises: an outer cowl (11), comprising: a structure (17), comprising at least one opening (19); a panel (21), pivotably mounted about an axis (31) between a closed position and an open position; and a system (30) for actuating the panel, designed to lock the panel in closed position and to move same between the closed position and the open position thereof. Said pod is characterised in that the actuation system comprises: a lateral connecting rod (43), connected to the panel (21) and to the structure (17), pivoting relative to the structure (17) about a first pivoting axis (51) and about a second pivoting axis (53); and a linear actuator (35), attached to said lateral connecting rod, the actuator system being designed to move the lateral connecting rod during the extension of said actuator and so that the lateral connecting rod exerts a force on the panel during the movement thereof, pivoting said panel about the axis thereof.