Flexible Veil Thrust Reversal for Turbofan Mass Reduction

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Solution Overview

Problem

Existing turbofan engines with reversing doors are heavy and require complex mechanisms for controlling secondary flow, necessitating a lighter and more efficient alternative for thrust reversal.

Innovation Solution

A dual-flow turbofan engine design featuring flexible sails and rotating arms that can close off the secondary flow path, utilizing a movable cowl and actuators to control the position of the arms and flexible veils to deflect secondary flow, replacing traditional reversing doors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional reversing doors are used to control secondary flow, then effective thrust reversal is achieved, but the engine mass increases and device complexity increases

Engineering Contradiction:

Improvethrust reversal effectivenessVSAvoidengine mass

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The patent replaces rigid reversing doors with flexible veils made of fabric panels. These flexible veils are deployed from storage pockets in the nacelle and can be inflated or pressurized to form effective barriers against the secondary flow, achieving thrust reversal without the mass penalty of traditional rigid door mechanisms

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The thrust reversal system is divided into multiple independent flexible veils rather than a single large door. Each veil can be independently deployed and controlled, allowing for modular operation that reduces overall system mass while maintaining effectiveness through coordinated deployment of multiple segments

Inventive Principle:

Principle #1Segmentation

2Reliability

If traditional reversing doors are used, then thrust reversal is achieved, but device complexity and mechanism complexity increase

Engineering Contradiction:

Improvethrust reversal effectivenessVSAvoidcontrol mechanism complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The flexible veils are stored in compact pockets within the nacelle structure and can be rapidly deployed when needed. This eliminates the need for complex rotating door mechanisms and reduces the overall device complexity while maintaining thrust reversal effectiveness

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The system transitions from static rigid doors to dynamic flexible veils that can be deployed and retracted as needed. The veils can be inflated or pressurized to form barriers only when thrust reversal is required, reducing complexity by eliminating constant mechanical structures

Inventive Principle:

Principle #15Dynamics

Data Source

PatentEP3845753B1Turbofan engine having a system for sealing the bypass flow passage comprising fabric panels

Publication Date: 2022.12.21 AIRBUS OPERATIONS (SAS)

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AI summary

The invention relates to a turbofan engine (100) comprising a nacelle (102) delimiting a sideflow (204) from a secondary flow (208) and comprising a fixed structure (206) including a cascade support (218) with cascades (219), a movable cowling (216) that is translationally movable between an advanced and a retracted position, arms (250), each of which is rotationally movable on the cascade support (218) between a retracted and a deployed position and comprising a distal and a proximal end, for each pair of adjacent arms (250), a flexible curtain (252) extending angularly between the two arms (250) the outer edge of which is fixed to the cascade support (218) and the distal end of each arm (250) is fixed along the inner edge, a rod (254) articulated between the distal ends, and actuators for moving the movable cowling (216), and a maneuvering system that moves each arm (250).Replacing the reversing gates and their drive mechanisms with flexible sails and a set of rotating mobile arms allows for a reduction in mass.