Thrust Reverser Door Kicker Frame Dynamics
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Thrust reverser doors in turbofan gas turbine engines face a trade-off between optimal performance and efficiency, as larger doors provide better braking but are heavier and incur more losses when stowed, necessitating a balance in design to minimize losses while maintaining effectiveness.
Innovation Solution
The implementation of a hybrid single-and-double skin construction with a kicker frame that adjusts the effective length of the thrust reverser doors, redirecting airflow to enhance deceleration efficiency without altering the geometric length, thereby optimizing performance and reducing manufacturing and maintenance complexities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If larger doors are used to improve braking performance, then deceleration efficiency is improved, but weight increases and losses when stowed increase
Solution Approach 1:
The patent applies a hybrid single-and-double skin construction that allows the door structure to dynamically adjust its effective length. The door can extend to a first effective length for optimal braking performance, and retract to a second effective length for reduced drag when stowed. This dynamic adjustment resolves the contradiction by allowing the door to have large effective length during braking operations while minimizing weight penalties during stowed operations.
2Productivity
If larger doors are used to improve braking performance, then deceleration efficiency is improved, but losses when stowed increase
Solution Approach 1:
The hybrid single-and-double skin construction enables the door to dynamically change its effective length between a first length for braking and a second length for stowed operations. This reduces the drag losses when stowed while maintaining optimal braking performance when deployed.
Solution Approach 2:
The patent changes the effective length parameter of the door based on operational requirements. By adjusting the effective length between a first value for braking and a second value for stowed operations, the system optimizes both braking performance and reduces energy losses during stowed operations.
3Productivity
If door length is increased to improve braking performance, then deceleration efficiency is improved, but manufacturing complexity increases
Solution Approach 1:
The hybrid single-and-double skin construction provides a dynamic solution that adjusts effective door length without requiring complex manufacturing processes. The construction uses a combination of single skin and double skin sections that can be manufactured using standard techniques, avoiding the need for overly complex structures while still achieving variable effective length.
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
This solution improves the thrust reverser's braking performance by adjusting the effective length of the doors, enhancing deceleration efficiency while minimizing weight and manufacturing costs, and allowing for commonality across multiple aircraft designs.
Implementation Method 1
a kicker frame that adjusts the effective length of the thrust reverser doors, redirecting airflow to enhance deceleration efficiency
Data Source
Figure 1
Figure 2~3
Figure 4~7
AI summary
A thrust reverser door (24, 26) provides in one aspect a separation of structural and aerodynamic functions through the provision of individual structures (42, 48, 50). In some embodiments, an aerodynamic element (50) is adjustable in position, while in other embodiments, the relative positions are fixed. An exemplary aerodynamic element extends radially into the reverser flow (A2) to redirect the flow away from the door surface.