Decoupled Blocker Door Structure for Impact and Acoustic Performance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing blocker doors for aircraft thrust reversers suffer from low impact tolerance, high production costs, and compromised acoustic and mechanical performance due to structural design limitations.
Innovation Solution
A blocker door design with a structural frame decoupled from the resistive skin, where the frame covers less than 50% of the surface and is held at a distance, allowing the resistive skin to absorb impacts while maintaining mechanical strength and acoustic performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the structural frame covers a large surface area of the resistive skin, then the mechanical strength of the blocker door is improved, but the impact tolerance is reduced and weight increases
Solution Approach 1:
The blocker door is segmented into distinct functional zones: a structural frame providing mechanical strength at critical locations, and a resistive skin covering the remaining surface that absorbs impacts. This segmentation allows each component to optimize its specific function without compromising the other.
Solution Approach 2:
Different parts of the blocker door have different properties: the structural frame has high mechanical strength with minimal surface coverage (less than 50%), while the resistive skin has high impact tolerance and acoustic absorption properties. This local differentiation resolves the contradiction by assigning appropriate properties to appropriate locations.
2Strength
If the structural frame is coupled closely to the resistive skin, then the mechanical strength is improved, but the acoustic performance is compromised
Solution Approach 1:
A gap or intermediary space is introduced between the structural frame and the resistive skin. This gap acts as an acoustic mediator that allows sound waves to pass through and be absorbed by the resistive skin, while the structural frame maintains its mechanical support function at a distance.
Solution Approach 2:
The resistive skin functions as a porous acoustic material that absorbs sound waves. By decoupling it from the rigid structural frame, the porous structure can effectively interact with acoustic waves without being constrained by the frame, thereby improving acoustic performance.
3Strength
If the structural frame covers more surface area, then the mechanical strength is improved, but the production cost increases
Solution Approach 1:
Instead of providing structural frame coverage over the entire surface area, the design uses partial action by limiting the frame coverage to less than 50% of the surface. This partial coverage is sufficient to provide the required mechanical strength while significantly reducing material usage and production costs.
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 improves acoustic performance by decoupling the structural frame from the resistive skin, ensuring safe operation and efficient noise attenuation.
Implementation Method 1
an acoustically porous resistive skin (16) intended to be located on the same side as a flow duct through which an air flow passes
Data Source
AI summary
A blocker door for a thrust reverser includes: a structural frame which is configured to ensure the mechanical strength of the blocker door; an alveolar core; and an acoustically porous resistive skin which is intended to be located on the air flow side. The structural frame covers less than 50% of the surface of the resistive skin and is kept at a distance from the resistive skin. This separation between the structural frame and the resistive skin makes it possible to improve the impact behavior 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.