Split Cascade Thrust Reverser Reducing Nacelle Volume
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Solution Overview
Problem
Conventional thrust reverser cascades have a large package size, occupying significant volume in the aircraft nacelle, which limits clearance and hinders airflow, maintenance access, and increases drag.
Innovation Solution
A split cascade system comprising a fixed and translating cascade portion, where the translating sleeve deploys to engage with a catch, forming a coupled assembly that redirects airflow during thrust reverser activation, reducing the overall package size and enhancing nacelle clearance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a conventional single-piece cascade is used, then the structural strength is sufficient, but the package size is large occupying significant volume in the nacelle
Solution Approach 1:
The cascade is divided into multiple segments (first cascade portion and second cascade portion) that can be independently positioned. The translating cascade portion moves relative to the fixed cascade portion, allowing the overall package size to be reduced while maintaining structural integrity through the coupling mechanism between segments.
2Area of stationary object
If a conventional single-piece cascade is used, then the structural integrity is maintained, but the clearance in the nacelle is reduced limiting airflow and maintenance access
Solution Approach 1:
By segmenting the cascade into fixed and translating portions, the design creates space for the translating portion to move, thereby increasing nacelle clearance. The coupling mechanism ensures structural integrity is maintained during translation and when segments are engaged.
Solution Approach 2:
The cascade transitions from a static single-piece structure to a dynamic multi-segment structure where the translating cascade portion can move between stowed and deployed positions. This dynamic capability increases clearance during operation while maintaining structural integrity through the coupling mechanism.
3Device complexity
If a conventional single-piece cascade is used, then the structure is simple, but the drag is increased due to reduced clearance
Solution Approach 1:
The dynamic translation of the cascade portion optimizes aerodynamic performance by adjusting the cascade position based on operational requirements. During thrust reversal, the cascade translates to provide optimal airflow direction while minimizing drag, outweighing the additional mechanical complexity.
4Volume of moving object
If the cascade is made smaller to reduce package size, then the clearance is improved, but the coupling mechanism complexity increases
Solution Approach 1:
The coupling mechanism uses a bracket and catch system that connects cascade segments. This segmentation approach allows for reduced package size while the coupling mechanism provides a straightforward method for joining segments, balancing complexity reduction with functional requirements.
Data Source
AI summary
A cascade assembly is provided for installation in an aircraft nacelle. The cascade assembly comprises a first cascade portion fixed to a non-movable portion of the nacelle. The first cascade portion comprises a bracket. A second cascade portion is fixed to a translating sleeve portion of the nacelle. The second cascade portion comprises a catch. The bracket is configured to receive the catch in response to the translating sleeve portion being in a deployed position.