Thrust Reverser Pivoting Doors Sliding Rear Shell Ring
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Solution Overview
Problem
Conventional thrust reversers with pivoting doors and fixed or movable rear shell rings face constraints such as increased mass, reduced thrust reversal performance, and complex actuation systems, which hinder efficient counter-thrust generation and flight performance.
Innovation Solution
A thrust reverser design featuring a fixed structure with a movable rear shell ring and a simplified actuation system using tie rods to synchronize the movement of doors and the ring, reducing the mass and complexity of the actuation system while enhancing flight performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a fixed rear shell ring is used, then the structure is simple, but the doors must collide with it during opening requiring reduced distance between rotation axis and rear, increasing girder dimension and reducing thrust reversal performance
Solution Approach 1:
The rear shell ring is made movable instead of fixed, allowing it to translate in the longitudinal direction during door operation. This dynamic adjustment enables the ring to move away from the door path during opening, eliminating the need for door-girder collisions and allowing optimized door dimensions for better thrust reversal performance.
Solution Approach 2:
The actuation system is segmented into two independent tie rods: one connecting the actuator to the door for pivoting, and another connecting the actuator to the rear shell ring for translation. This segmentation allows independent control of door and ring movements while maintaining synchronization through the common actuator.
2Device complexity
If a fixed rear shell ring is used, then the structure is simple, but the opening angle of doors is limited requiring increased door and nacelle length, increasing mass
Solution Approach 1:
The movable rear shell ring translates longitudinally to create additional space during door opening, enabling larger door opening angles without increasing door or nacelle length. This maintains compact dimensions and reduces mass while achieving satisfactory counter-thrust flow cross-section.
3Adaptability or versatility
If conventional movable rear shell ring reversers are used, then door geometry constraints are resolved, but the actuation system becomes complex and bulky
Solution Approach 1:
Both the door pivoting and rear shell ring translation are driven by the same actuator through two tie rods. This merging of actuation functions into a single actuator reduces the number of actuators from multiple independent ones to one, significantly simplifying the actuation and control system.
Solution Approach 2:
The tie rods serve as intermediary mechanical elements that transmit the actuator's linear motion to both the door (for pivoting) and the rear shell ring (for translation). This intermediary mechanism enables coordinated movement of multiple components through a single actuator, reducing system complexity.
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 solution simplifies the actuation system, reduces the mass of the reverser, and improves thrust reversal performance by synchronizing the movement of doors and the ring, thereby enhancing both direct and reverse thrust configurations.
Implementation Method 1
an actuator configured to move the door between a closed position in which the door forms a trailing edge of the propulsion unit and an open position in which the door is positioned to redirect a fluid flow towards a front of the propulsion unit
Implementation Method 2
a second tie rod having a first end connected to the movable element of the actuator and a second end connected to the ring, the second tie rod being configured to translate the ring in response to movement of the actuator
Implementation Method 3
means for guiding the ring between the forward and retracted positions
Data Source
AI summary
A thrust reverser including doors, a rear shell ring and an actuation system for synchronising the pivoting of the doors and the translation of the rear shell ring.