Aircraft Nacelle Core Cowl Support Structure
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Solution Overview
Problem
Existing aircraft propulsion system mounting cowls face inefficiencies in structural support and load distribution, particularly in the hinging mechanisms, which can lead to suboptimal aerodynamic performance and increased stress on components.
Innovation Solution
The proposed solution involves a support structure with parallel longitudinal and crossover rails, pivot connections to a turbine engine case, and a latch system for cowls, along with a firewall for enhanced structural integrity, utilizing materials like titanium for key components to improve stability and aerodynamics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If distinct hinges are used to mount inner and outer structures separately to the pylon, then the mounting system achieves adaptability and versatility in configuration, but the device complexity increases due to multiple separate hinge locations and non-coaxial axes of rotation
Solution Approach 1:
The patent combines the inner fixed structure and outer sleeve into a single integrated assembly that rotates about a common coaxial axis. This merging eliminates the need for separate hinges at different locations, reducing the number of hinge components from multiple distinct hinges to a unified hinge system while maintaining the adaptability of the mounting configuration.
Solution Approach 2:
The common coaxial hinge system serves multiple functions simultaneously: it supports both the inner fixed structure and outer sleeve, provides a unified rotation axis for both components, and simplifies the mounting mechanism while maintaining the versatility of the propulsion system configuration.
2Adaptability or versatility
If separate hinge locations with non-coaxial axes are used for inner and outer structures, then adaptability in mounting is achieved, but stress distribution becomes suboptimal leading to increased component stress
Solution Approach 1:
By merging the rotation axes of the inner fixed structure and outer sleeve into a single common coaxial axis, the patent creates a unified load path that distributes stress more evenly across the hinge components and supporting structures, eliminating the stress concentration issues associated with non-coaxial hinge arrangements.
3Adaptability or versatility
If multiple separate hinge components are used, then adaptability in mounting configuration is achieved, but manufacturing precision requirements increase due to multiple alignment requirements
Solution Approach 1:
The patent reduces the number of hinge components by combining them into a unified system with a common coaxial axis. This merging eliminates the need for precise alignment between multiple separate hinge locations, thereby reducing manufacturing precision requirements while maintaining the adaptability of the mounting configuration.
Data Source
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AI summary
A nacelle (22) is provided that includes an outer structure (24) and an inner structure (26). The inner structure (26) includes a support structure (54), a first core cowl (48) and a second core cowl (48). The support structure (54) includes a plurality of first hinges (56), a plurality of second hinges (56), a plurality of longitudinal rails (74) and a plurality of crossover rails (76) spaced longitudinally along and connected to the longitudinal rails (74). Each of the first hinges (56) is connected to a respective one of the crossover rails (76) at a first distal end (92) of the respective crossover rail (76). Each of the second hinges (56) is connected to a respective one of the crossover rails (76) at a second distal end (90) of the respective crossover rail (76). The first core cowl (48) is pivotally mounted to the support structure (54) by the first hinges (56). The second core cowl (48) is pivotally mounted to the support structure (54) by the second hinges (56).