Flexible Sail Thrust Reverser for Turbofan Mass Reduction
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Solution Overview
Problem
Existing dual-flow turbojet engines rely on heavy thrust reversal systems, such as inversion doors, which are not optimal for reducing mass and improving efficiency.
Innovation Solution
The implementation of flexible sails and a pneumatic deployment system that deploys and folds the sails to control the secondary flow vein, utilizing a pressurization and depressurization system to move the sails between deployed and folded positions, reducing mass and enhancing aerodynamic efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If inversion doors are used for thrust reversal, then effective counter-thrust is achieved, but the system becomes heavy and complex
Solution Approach 1:
The patent replaces rigid inversion doors with flexible sails that can be deployed and retracted. These sails are made of flexible material and can be inflated or deflated to control the secondary flow, significantly reducing the mass of the thrust reversal system while maintaining effectiveness
Solution Approach 2:
The patent introduces a pneumatic system with inflatable bladders to deploy and retract the flexible sails. By using pneumatic pressure to inflate the bladders, the sails are pushed outward to block the secondary flow vein, and deflation retracts them, providing a lightweight actuation mechanism
2Reliability
If rigid thrust reversal mechanisms are used, then reliable flow control is achieved, but aerodynamic efficiency is reduced
Solution Approach 1:
The patent employs dynamically deployable and retractable flexible sails rather than fixed rigid structures. The sails can be deployed when thrust reversal is needed and retracted during normal operation to maintain optimal aerodynamic flow, thus improving aerodynamic efficiency while preserving reliable flow control when required
Solution Approach 2:
The patent changes the physical state of the thrust reversal elements from rigid to flexible, and controls their deployment through pneumatic pressure changes. This allows the system to adapt its configuration based on operational requirements, maintaining aerodynamic efficiency during cruise while providing reliable thrust reversal when needed
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
This solution results in a lighter assembly with improved aerodynamic performance and efficiency, adjusting the thrust reverser's efficiency and aeramatch ratio, while maintaining effective counter-thrust capabilities.
Implementation Method 1
a pneumatic system arranged to move the second edge of each sail in order to move said sail from the folded position to the deployed position and to move the second edge of each sail in order to move said sail from the deployed position to the folded position, where the pneumatic system comprises: a rigid main tube fixed inside the movable cover
Implementation Method 2
a pressurization and depressurization system which, alternately, generates pressure in the main tube and therefore in each secondary tube to inflate them when moving from the forward position to the rearward position, or generates a depression in the main tube and therefore in each secondary tube to deflate them
Implementation Method 3
a Venturi tube with an inlet section, an outlet section and an intermediate section between the inlet section and the outlet section
Data Source
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AI summary
The invention relates to a turbofan engine (100) with a nacelle (102) and a duct (204), wherein the nacelle comprises a movable cowling (216) for defining a window (220) between the duct and the outside, sails (252) with a first edge fixed to the movable cowling and alternately assuming a folded or deployed position across the duct (204), and a pneumatic system (350) for moving a second edge of the sails from the folded position to the deployed position and vice versa. The pneumatic system (350) comprises a rigid main tube (352), for each sail (252), at least one extendable secondary tube (354) fixed to a second edge of said sail (252), and a pressurization and depressurization system that alternately generates pressure or a vacuum in each secondary tube (354). Replacing the reversing gates and their drive mechanisms with flexible sails and a pneumatic system allows for a reduction in mass.