Mixed Flow Turbofan Thrust Reverser Duct Translation
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Solution Overview
Problem
Current pre-exit pivot door thrust reversers for turbofan gas turbine engines face challenges in efficiently redirecting exhaust streams for effective thrust reversal, particularly in accommodating the mixed exhaust stream from both the core and bypass airflow, which affects the deceleration of aircraft during landing.
Innovation Solution
The thrust reverser design includes pivotally mounted doors, a translationally mounted exhaust duct, and actuators with connected links and translating members, allowing for the linear translation and pivotal movement of the doors and duct to redirect the mixed exhaust stream upstream, thereby generating reverse thrust.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If pre-exit pivot door thrust reversers are used to redirect exhaust streams, then thrust reversal capability is provided, but the system cannot efficiently accommodate mixed exhaust streams from both core and bypass airflow
Solution Approach 1:
The exhaust duct is segmented into multiple sections that can translate independently relative to each other and to the reverser doors. This segmentation allows the duct to accommodate the complex flow patterns of mixed exhaust streams while maintaining effective thrust reversal capability through coordinated movement of the segmented sections.
Solution Approach 2:
The exhaust duct transitions from a static structure to a dynamic one with translational degrees of freedom. The duct sections can move relative to each other to adapt to varying exhaust flow conditions, improving both adaptability to mixed streams and maintaining reliability of thrust reversal through active positioning.
2Adaptability or versatility
If the exhaust duct is made translationally mounted to allow movement, then adaptability to redirect exhaust stream is improved, but the device complexity increases due to additional mounting mechanisms
Solution Approach 1:
The translational mounting mechanism is merged with the existing thrust reverser structure. The actuator system that controls reverser door movement is integrated with the exhaust duct translation control, allowing a single control system to manage both door actuation and duct positioning, thereby reducing overall device complexity.
Solution Approach 2:
The mounting mechanism serves multiple functions: it provides translational support for the exhaust duct, enables adaptive redirection of exhaust streams, and works in conjunction with the reverser doors to achieve thrust reversal. This multi-functionality reduces the need for separate specialized components, simplifying the overall system.
3Ease of operation
If actuators with connected links and translating members are used to move doors and duct, then operational flexibility is improved, but the device complexity increases
Solution Approach 1:
The linkage system incorporates translating members that provide dynamic adjustment capability. These members allow the actuator links to change length or position during operation, enabling the system to adapt to different operational conditions and achieve greater flexibility in door and duct positioning while maintaining manageable complexity through standardized mechanical components.
Data Source
AI summary
A thrust reverser for a gas turbine engine includes a reverser door pivotally mounted to a frame, an exhaust duct translationally mounted to the frame and an actuator having an actuator rod connected to the reverser door and to the exhaust duct.