Aircraft Leading Edge Flap Arc Deployment and Seal
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Solution Overview
Problem
Existing aircraft leading edge flap systems, such as Krueger flaps, face challenges with high loads and resistance during deployment, limited curvature of the top surface, complex actuator assemblies, and increased weight and cost due to the need for additional mechanisms to achieve desired aerodynamic performance, especially during takeoff and landing.
Innovation Solution
The use of a geared rotary actuator assembly with a 6-bar linkage that moves the flap along an arc-shaped path without flipping it, allowing the top surface to maintain a larger curvature and avoiding the 'barn door' condition, coupled with a seal to cover notches in the deployed position, reducing drag and enhancing aerodynamics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a traditional actuator assembly is used to deploy the Krueger flap, then the flap can be moved between stowed and deployed positions, but high loads and resistance are generated during deployment
Solution Approach 1:
The patent employs an arc-shaped deployment path for the Krueger flap, allowing it to move along a curved trajectory rather than a linear path. This curvature enables the flap to maintain better aerodynamic alignment during deployment, reducing resistance and loads on the actuator assembly while facilitating smoother operation between stowed and deployed positions.
2Adaptability or versatility
If additional mechanisms are added to achieve desired aerodynamic performance, then aerodynamic efficiency is improved, but device complexity and cost increase
Solution Approach 1:
The patent integrates multiple functions into the actuator assembly, including the crank mechanism that simultaneously provides rotational motion conversion and structural support, while the seal serves both aerodynamic sealing and structural integration purposes. This multi-functionality reduces the need for separate dedicated components, thereby simplifying the overall device complexity while maintaining aerodynamic performance.
3Strength
If the top surface curvature is increased for aerodynamic performance, then lift is improved, but the flap design becomes more complex
Solution Approach 1:
The Krueger flap is designed with a curved top surface that maintains larger curvature throughout its deployment arc. This curvature is integrated into the flap's structural design, allowing it to generate enhanced aerodynamic lift while the curved deployment path naturally accommodates the curvature without requiring additional complex mechanisms or adjustment systems.
4Weight of moving object
If the actuator assembly is made lighter and simpler, then weight and cost are reduced, but the ability to move the flap against aerodynamic loads may be compromised
Solution Approach 1:
The arc-shaped deployment path is optimized to work with the aerodynamic loads, allowing the lighter actuator assembly to move the flap more efficiently by maintaining better airflow alignment during deployment. This reduces the effective aerodynamic resistance the actuator must overcome, enabling reliable operation with reduced weight and complexity.
Solution Approach 2:
The seal is strategically positioned to cover the notch in the deployed position, acting as an intermediary that improves aerodynamic flow over the flap. This aerodynamic benefit reduces the overall loads on the actuator system, enabling lighter construction while maintaining reliable flap deployment capability.
Data Source
Figure 1
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Figure 3A~3B
AI summary
Example actuator assemblies (224) to deploy aircraft leading edge flaps and seals for aircraft leading edge flaps (202) are described herein. An example apparatus includes an aircraft flap (202) that is movable between a stowed position and a deployed position. The flap includes a top panel (308). A notch (372) is formed in the top panel and extends into a side of the top panel near a trailing edge (313) of the flap. The example apparatus also includes a seal (1000) coupled to the flap. The seal (1000) is movable to cover the notch (372) when the flap (202) is in the deployed position.