Lightweight Thrust Reverser Flap with Acoustic Resonator

Solution Overview

Problem

Existing thrust reverser flaps for turbojet engines are heavy and complex, which increases the in-flight load and reduces efficiency, while also requiring additional structural elements to maintain acoustic and obstructing functions.

Innovation Solution

A thrust reverser flap design featuring a single pierced wall that acts as both a structural stiffener and an acoustic component, utilizing the existing movable structure to form a second wall in the direct jet position, thereby reducing weight and complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional thrust reverser flap with two walls is used to achieve acoustic and obstructing functions, then the acoustic function and obstructing function are maintained, but the weight and complexity of the flap increase

Engineering Contradiction:

Improveacoustic functionVSAvoidflap weight

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The patent merges the acoustic function and obstructing function into a single integrated wall structure. The pierced wall combines the acoustic resonance chamber function with the flow obstruction function, eliminating the need for separate second wall and reducing overall flap weight while maintaining both functions

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The single pierced wall serves multiple functions simultaneously: it acts as the primary obstruction element, forms the acoustic resonance chamber boundary, and provides structural stiffening. This multi-functional design reduces the number of components needed while maintaining acoustic and obstructing performance

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If a traditional thrust reverser flap with two walls is used to achieve acoustic and obstructing functions, then the acoustic function and obstructing function are maintained, but the device complexity increases

Engineering Contradiction:

Improveacoustic functionVSAvoidflap structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the acoustic function and obstructing function into a single integrated wall structure. The pierced wall combines the acoustic resonance chamber function with the flow obstruction function, eliminating the need for separate second wall and reducing overall flap weight while maintaining both functions

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The wall is pierced with strategically placed openings that segment the flow path while maintaining the acoustic resonance chamber integrity. This segmentation allows the single wall to perform both acoustic and obstructing functions without requiring additional structural elements

Inventive Principle:

Principle #1Segmentation

3Weight of moving object

If a single pierced wall flap design is used, then the weight and complexity are reduced, but the pressure differential and air recirculation may be affected

Engineering Contradiction:

Improveflap weightVSAvoidpressure differential

Core Design Contradiction:

Weight of moving objectVSStress or pressure

Solution Approach 1:

The wall features localized piercing patterns with varying density and size across different regions. This local quality variation optimizes flow distribution and pressure management, allowing the single wall to maintain adequate pressure differential while enabling weight reduction through the pierced design

Inventive Principle:

Principle #3Local quality

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

The design achieves a lighter thrust reverser with reduced air recirculation and lower pressure differential, while maintaining acoustic and obstructing functions, thereby enhancing the overall efficiency and performance of the thrust reverser.

Implementation Method 1

said acoustic section forming with the structure of said wall an acoustic resonator

Methodology Applied

Scientific EffectAcoustic resonance: Resonance

Data Source

PatentUS12209556B2Thrust reverser provided with a lightweight thrust reverser flap

Publication Date: 2025.01.28 SAFRAN NACELLES

AI summary

A thrust reverser includes a fixed structure and a movable structure defining an air stream, a flap including a single wall perforated on the surface thereof, and a structure strengthening the flap and having an acoustic function. The flap being articulated between the fixed structure and the movable structure to allow in a direct jet position, disposing the wall along an acoustic section of the movable structure and allowing the circulation of an air flow through the air stream, the acoustic section forming with the structure of the wall an acoustic resonator, and in a reverse jet position, disposing the wall to deflect an air flow passing through the air stream and allow the passage through the wall and through the air stream of a portion of the air flow deflected by the flap.