Variable Ejector Nozzle with Discrete Movable Parts
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Solution Overview
Problem
Existing variable section nozzles for turbofan aircraft engines face challenges such as high power requirements, sealing issues, and increased cost and mass due to the need for powerful actuating means, particularly in devices with dual functions like thrust reversers and air relief systems.
Innovation Solution
A propulsion assembly with a discrete variable section nozzle featuring deployable cowls or pivoting elements that can occupy discrete positions, allowing for asymmetrical operation to adapt thrust according to altitude, optimizing engine performance while reducing complexity and energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If powerful actuating means are used to enable dual functions (thrust reverser and air relief device), then the nozzle can perform both functions, but the cost and mass of the device increase
Solution Approach 1:
The patent integrates thrust reverser and air relief device functions into a single nozzle structure. The movable part can operate in different configurations: fully open for air relief, partially open for thrust reversal, and closed for normal operation. This multi-functional design eliminates the need for separate actuating systems for each function, reducing overall device mass and cost while maintaining versatility.
2Adaptability or versatility
If powerful actuating means are used to enable dual functions (thrust reverser and air relief device), then the nozzle can perform both functions, but the cost of the device increases
Solution Approach 1:
The patent integrates thrust reverser and air relief device functions into a single nozzle structure. The movable part can operate in different configurations: fully open for air relief, partially open for thrust reversal, and closed for normal operation. This multi-functional design eliminates the need for separate actuating systems for each function, reducing overall device mass and cost while maintaining versatility.
3Ease of operation
If continuous position control systems are used, then precise thrust adjustment is possible, but the system complexity increases
Solution Approach 1:
The patent divides the nozzle outlet into multiple discrete adjustable sections or annular zones. Each zone can be independently controlled to different degrees of opening, allowing precise thrust adjustment through combinatorial configurations. This segmentation approach enables fine-grained control without requiring continuous position control of the entire nozzle, simplifying the overall control system while maintaining adjustment precision.
Data Source
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AI summary
The invention relates to a nacelle for a propulsion assembly with a variable section nozzle comprising a nacelle (1), housing a turbojet (3), of the twin-flow type. The propulsion assembly comprises: - a fixed part, carried by the inner half-nacelle (1int) defined by a vertical plane of symmetry of the nacelle, and - a movable part (20) carried by the outer half-nacelle (1ext), said movable part containing or releasing a part of the secondary flow, depending on its position, open or closed, said movable part being able to take only a discrete number of positions, greater than or equal to three positions, determining in particular a closed position, a fully open position, and one or more intermediate positions called semi-open.