Split Flap Track Fairing for Reduced Drag
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional flap track fairings on aircraft with swept wings face limitations in reducing drag and fuel burn due to their restricted width, which necessitates a thicker frontal profile and increased drag, limiting the efficiency of flap deployment mechanisms.
Innovation Solution
A split flap track fairing system with a forward immovable portion and an aft movable portion, where the movable portion is attached to the flap deployment mechanism or the flap's lower surface, allowing lateral movement and incorporating flow deflectors to manage airflow and prevent separation, resulting in a thinner profile and reduced drag.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the flap track fairing width is increased to accommodate lateral travel of the deployment mechanism, then the mechanism can move freely without structural interference, but the frontal profile thickness increases thereby producing more drag force and more detached flow area
Solution Approach 1:
The flap track fairing is divided into a fixed forward portion and a movable aft portion that can separate along a separation line. This segmentation allows the aft portion to move with the flap deployment mechanism while the forward portion remains stationary, enabling adequate lateral travel space without increasing the overall frontal profile thickness and associated drag.
Solution Approach 2:
The aft portion of the flap track fairing is designed to be movable rather than fixed, allowing it to dynamically adjust its position as the flap deployment mechanism moves laterally. This dynamic capability provides the necessary clearance for mechanism operation without permanently increasing the fairing's frontal profile.
2Ease of operation
If the flap track fairing width is increased to accommodate lateral travel of the deployment mechanism, then the mechanism can move freely without structural interference, but the detached flow area on the suction side of the wing flap increases
Solution Approach 1:
By segmenting the fairing into fixed and movable portions, the design provides lateral travel clearance without permanently increasing the frontal profile, thereby minimizing the detached flow area that would otherwise occur with a thicker fairing profile.
3Use of energy by moving object
If a pivoted flap track fairing is used to confine lateral travel within the fairing width, then fuel burn efficiency improves, but the fairing width is restricted by the minimum width needed to accommodate the deployment mechanism
Solution Approach 1:
The fairing is segmented into a stationary forward portion and a movable aft portion. This allows the system to achieve the fuel burn efficiency of a narrow fairing profile while the movable aft portion provides the necessary lateral travel accommodation for the deployment mechanism.
Solution Approach 2:
The movable aft portion dynamically adjusts to accommodate the deployment mechanism's lateral travel, enabling the fairing to maintain a narrow effective profile during cruise (for fuel efficiency) while providing adequate clearance when flaps are deployed.
4Object-generated harmful factors
If the flap track fairing frontal profile is made thinner to reduce drag, then fuel burn efficiency improves, but the fairing may not accommodate the lateral travel of the deployment mechanism
Solution Approach 1:
The fairing is divided into a fixed forward portion with a thin profile for reduced drag and a movable aft portion that provides the necessary lateral travel accommodation. This segmentation allows the front profile to remain thin while the rear movable portion handles the mechanism's lateral movement requirements.
Solution Approach 2:
The movable aft portion dynamically provides lateral clearance as needed during flap operation, allowing the fairing to maintain a thin frontal profile for reduced drag while accommodating the deployment mechanism's lateral travel when required.
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 achieves a 10-20% reduction in flap track fairing frontal area, leading to a 0.4-1% decrease in total drag during cruise flight, enhancing fuel efficiency and reducing noise and separation risks.
Implementation Method 1
The movable aft portion of the flap track fairing includes flow deflectors installed at the separation border with the fixed forward portion. When the flap is extended, the deflectors have the function of deflecting the airflow away from the cavity opening that would otherwise be presented.
Data Source
AI summary
Flap track fairing systems are split into a forward immovably fixed portion and an aft movable portion. The fixed forward portion is immovably attached to the main wing structure of an aircraft while the movable aft portion is attached either to the movable components of the flap deployment mechanism or to the lower surface of the flap. A separation line between the forward movable portion and the aft fixed portion is provided such that the movable portion does not interfere structurally with the flap fairing structure during a flap extension/retraction cycle. An airflow deflector is positioned near a forward separation edge of the aft fairing portion so as to be positioned within a gap defined between the forward edge of the aft fairing portion and a rearward edge of the forward fairing portion when the flap is in the deployed configuration thereof to thereby deflect airflow away from the interior space of the fairing.