Variable Nozzle Control for Aircraft Turbojet Fuel Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing control methods for variable nozzle sections in turbojet engine nacelles result in excessive fuel consumption and wear of actuating systems due to frequent position changes during flight phases, particularly during cruise where positions are not optimally suited to changing altitudes and flight conditions.
Innovation Solution
A method for controlling the position of a variable nozzle section that determines optimal positions based on flight phases, altitude, and motor regime, allowing displacements only when time intervals or position differences exceed predetermined thresholds, thereby optimizing fuel consumption and reducing wear on control and actuating systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the nozzle position is frequently adjusted to match changing flight conditions, then fuel consumption is optimized, but wear on control and actuating systems increases
Solution Approach 1:
The patent implements periodic action by introducing a time interval threshold that limits how frequently nozzle position adjustments can occur. The control system calculates the time elapsed since the last position change and only allows adjustment when this interval exceeds the predetermined threshold, thereby reducing actuator wear while maintaining fuel efficiency through periodic optimization
Solution Approach 2:
The patent applies dynamics by making the nozzle position adjustment system adaptive rather than static. The control system dynamically evaluates flight conditions (altitude, speed, thrust) and determines optimal positions based on current operational state, allowing the system to respond flexibly to changing conditions while incorporating wear-reduction logic through time interval constraints
2Device complexity
If discrete predetermined positions are used for the nozzle, then control system complexity is reduced, but fuel consumption increases due to excessive position changes
Solution Approach 1:
The patent applies parameter changes by transitioning from discrete predetermined positions to continuous optimal position determination. The control system calculates the optimal nozzle position as a continuous value based on flight parameters (altitude, speed, thrust) rather than selecting from fixed discrete positions, thereby reducing fuel consumption while maintaining manageable control system complexity through systematic calculation methods
3Ease of operation
If predetermined positions are defined for different flight phases, then control system simplicity is maintained, but operational optimality deteriorates when flight conditions change during cruise
Solution Approach 1:
The patent implements feedback by continuously monitoring flight conditions (altitude, speed, thrust) and using this information to determine the optimal nozzle position. The control system receives feedback from sensors measuring current flight parameters and adjusts the nozzle position accordingly, maintaining both simplicity through systematic control logic and adaptability through real-time condition-based optimization
Solution Approach 2:
The patent applies preliminary action by pre-establishing the control logic and calculation methods for determining optimal nozzle positions across different flight phases. The system is pre-programmed with the optimization algorithms and decision-making framework, enabling it to adapt to changing conditions during cruise without requiring complex real-time reconfiguration
Data Source
AI summary
A method for controlling a position of a variable nozzle of an aircraft includes the following steps: setting the variable nozzle in a position P(t0) at a time t0 as a preliminary step; step A in which at each instant ti with 1<i<N, an optimal position P(ti) of the variable nozzle is determined according to magnitudes distinctive of the flight of the aircraft; step B measuring a time interval Δti defined as a difference between ti and t0; and step C by which a displacement of the variable nozzle in a position corresponding to the optimal position P(ti) is authorized when the time interval Δti is higher than a predetermined minimum threshold.