Decoupled Blocker Door Structure for Impact-Tolerant Thrust Reversers
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Solution Overview
Problem
Existing thrust reverser locking flaps in aircraft engines are sensitive to impact, have high production costs, and compromise mechanical strength and acoustic performance.
Innovation Solution
A locking flap design with a structural frame decoupled from the acoustically porous resistive skin, ensuring mechanical strength primarily through the frame while the skin absorbs impacts, and manufactured as a single-piece aero-acoustic box to reduce weight and cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the structural frame is integrated with the resistive skin in existing locking flap designs, then mechanical strength is ensured, but impact sensitivity increases and production costs rise
Solution Approach 1:
The locking flap is divided into two functionally independent parts: a structural frame that provides mechanical strength and a separate resistive skin that absorbs impacts. The skin is attached to the frame but can move independently, allowing it to deflect under impact without transmitting forces to the structural frame. This segmentation resolves the contradiction by allowing each component to optimize for its specific function.
Solution Approach 2:
The resistive skin is extracted from the integrated structure and treated as a separate element that can be optimally designed for impact absorption. The skin is made of a material and configuration specifically suited for withstanding aerodynamic shocks, while the structural frame focuses solely on providing mechanical support. This extraction allows the frame to be less sensitive to impact damage.
2Strength
If traditional multi-component locking flap designs are used, then mechanical strength and acoustic performance are achieved, but production costs and manufacturing complexity increase
Solution Approach 1:
The structural frame and resistive skin are combined into a single integrated component manufactured as one piece. This eliminates the need for separate manufacturing and assembly processes for multiple components, significantly reducing production costs and manufacturing complexity while maintaining the functional benefits of having distinct structural and acoustic elements.
Solution Approach 2:
The locking flap is manufactured as a single-piece composite structure combining different materials or material properties in one component. This allows the structural frame and resistive skin to be created simultaneously with optimized material distribution, reducing production steps and costs while ensuring both mechanical strength and acoustic performance.
3Strength
If the structural frame covers the entire surface of the resistive skin, then mechanical strength is maximized, but weight increases and acoustic performance deteriorates
Solution Approach 1:
The structural frame is designed to provide mechanical strength only where absolutely necessary, rather than covering the entire surface. The frame is positioned strategically to support the resistive skin and maintain structural integrity, while leaving large areas of the skin exposed for acoustic functionality and weight reduction. This local reinforcement approach minimizes weight while maintaining sufficient strength.
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 enhances impact tolerance, reduces weight and production costs, and maintains excellent acoustic performance by decoupling the structural frame from the resistive skin, allowing for efficient airflow redirection during thrust reversal.
Implementation Method 1
an acoustically porous resistive skin (91), intended to be located on the side of a vein (3) through which an airflow passes
Implementation Method 2
the structural frame (14) covers less than 50% of the surface of the resistive skin (16) and in that said structural frame is kept at a distance from the resistive skin (16)
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
The invention relates to a blocker door for a thrust reverser, preferably having screens and a sliding cover, the blocker door comprising: a structural frame (14) which is configured to ensure the mechanical strength of the blocker door; an alveolar core (17); and an acoustically porous resistive skin (16) which is intended to be located on the air flow side. The structural frame (14) covers less than 50% of the surface of the resistive skin (16) and is kept at a distance from the resistive skin (16), preferably more than 2 mm away from this skin. This separation between the structural frame and the resistive skin makes it possible to improve the impact behaviour of the blocker door. The resistive skin and the alveolar core preferably form a one-piece subassembly into which the structural frame fits. The door may be devoid of a rear skin.