Thrust Reverser Door for Variable Area Nozzle and Bypass Pressure Control
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Solution Overview
Problem
Existing aircraft engine systems face challenges in maintaining a suitable bypass pressure ratio as engine bypass ratios increase, leading to potential fan flutter issues, and traditional thrust reversers are complex and add weight while providing limited functionality beyond reverse thrust.
Innovation Solution
A thrust reverse variable area nozzle system with a pivotally movable thrust reverser door that can cover, partially uncover, or fully open reverse thrust openings to control bypass airflow, utilizing a pair of slide-pivot connections defining forward and aft pivot axes to manage airflow direction and pressure ratios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If variable area fan nozzle systems are used to maintain desired pressure ratio, then the bypass pressure ratio is maintained, but the device complexity increases and additional weight is added to the aircraft
Solution Approach 1:
The thrust reverser door is designed to perform multiple functions: it acts as both a thrust reverser for generating reverse thrust and as a variable area nozzle for controlling bypass airflow and maintaining pressure ratio. By integrating these two functions into a single component, the patent eliminates the need for a separate variable area nozzle system, thereby reducing device complexity and weight while maintaining the desired bypass pressure ratio
Solution Approach 2:
The patent combines the thrust reverser function and the variable area nozzle function into a single integrated system. The thrust reverser door serves dual purposes: deflecting bypass airflow for reverse thrust generation and controlling the cross-sectional area of the bypass airflow passage for pressure ratio management. This merging of functions resolves the technical contradiction by achieving the desired pressure ratio maintenance without adding the complexity and weight of a separate nozzle system
2Force
If traditional thrust reversers are used to generate reverse thrust, then the aircraft can be slowed effectively, but the device complexity increases and additional weight is added without providing additional functionality
Solution Approach 1:
The thrust reverser door is designed to perform multiple functions: it acts as both a thrust reverser for generating reverse thrust and as a variable area nozzle for controlling bypass airflow and maintaining pressure ratio. By integrating these two functions into a single component, the patent eliminates the need for a separate variable area nozzle system, thereby reducing device complexity and weight while maintaining the desired bypass pressure ratio
Solution Approach 2:
The thrust reverser door is designed with dynamic positioning capabilities, allowing it to assume different positions to perform different functions. The door can be positioned to deflect bypass airflow for reverse thrust generation or to control the cross-sectional area of the bypass airflow passage for pressure ratio management. This dynamic versatility allows a single component to replace multiple static components, reducing overall system complexity
3Use of energy by moving object
If engine bypass ratios are increased to improve fuel efficiency, then fuel consumption decreases, but it becomes increasingly difficult to maintain suitable bypass pressure ratio to avoid fan flutter
Solution Approach 1:
The thrust reverser door is designed with dynamic positioning capabilities, allowing it to assume different positions to perform different functions. The door can be positioned to deflect bypass airflow for reverse thrust generation or to control the cross-sectional area of the bypass airflow passage for pressure ratio management. This dynamic versatility allows a single component to replace multiple static components, reducing overall system complexity
Solution Approach 2:
The patent utilizes parameter changes in the bypass airflow passage cross-sectional area to maintain stable bypass pressure ratio. By adjusting the area through which bypass airflow passes using the thrust reverser door, the system can maintain optimal pressure ratio even as engine bypass ratios increase, thereby preventing fan flutter while allowing for improved fuel efficiency through higher bypass ratios
Data Source
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AI summary
A thrust reverse variable area nozzle system for a nacelle of an aircraft engine system may include a reverse thrust opening disposed in the nacelle, and a thrust reverser door pivotally movable relative to the nacelle for selectively covering the reverse thrust opening, wherein the thrust reverser door is pivotally movable between a first position for completely covering the reverse thrust opening, a second position for partially uncovering a forward portion of the reverse thrust opening and discharging a bypass airflow through the forward portion of the reverse thrust opening in a forward direction, and a third position for partially uncovering an aft portion of the reverse thrust opening and discharging the bypass airflow through the aft portion of the reverse thrust opening in an aft direction.