Aircraft Shock Control Fairing with Variable Cross-Sectional Profile
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Solution Overview
Problem
Conventional wing root fairings on aircraft fail to effectively manage shocks at the junction between the fuselage and wing, leading to increased wave drag and reduced lift at transonic speeds.
Innovation Solution
A shock control fairing with a varying cross-sectional profile that maximizes area at locations where shocks are expected to develop, extending chordwise along the wing root, and featuring a convex shape to modify pressure gradients and reduce airflow separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional wedge-shaped fillet fairing is used, then the structure is simple and easy to manufacture, but it fails to effectively manage shocks at transonic speeds resulting in increased wave drag
Solution Approach 1:
The fairing employs a variable cross-sectional profile where the maximum area is positioned at a specific location proximal to where shocks are expected to develop. This local optimization of geometry directly addresses shock management at critical locations while maintaining overall structural simplicity and manufacturability.
Solution Approach 2:
The invention changes the geometric parameters of the fairing by varying the cross-sectional area along its length, transitioning from a conventional constant or linear profile to a variable profile with a defined maximum area position. This parameter modification enables effective shock control at transonic speeds.
2Loss of energy
If the fairing cross-sectional area is increased to manage shocks, then wave drag is reduced, but the device complexity increases
Solution Approach 1:
Rather than uniformly increasing the entire fairing structure, the invention locally optimizes the cross-sectional area at specific locations. The maximum area is positioned proximal to shock development zones, providing targeted shock management without unnecessarily increasing overall device complexity.
Solution Approach 2:
The fairing is segmented into regions with different cross-sectional characteristics - a leading section, a maximum area section positioned to address shock locations, and a trailing section. This segmentation allows complex shock management functionality to be achieved through a relatively simple geometric variation rather than a completely complex structure.
3Loss of energy
If the fairing extends further chordwise to cover more shock regions, then shock management improves, but the length of the fairing increases
Solution Approach 1:
The fairing concentrates its shock management capability at the critical location where shocks are expected to develop, rather than uniformly distributing coverage. The maximum cross-sectional area is positioned proximal to the shock location, providing effective shock control in a compact chordwise footprint.
Solution Approach 2:
The fairing extends sufficiently chordwise to address the primary shock region without excessive over-extension. The variable cross-sectional profile ensures that the necessary shock management function is achieved with minimal additional length, avoiding unnecessary increase in fairing dimensions.
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 fairing reduces wave drag, moves shocks aft, and increases lift by modifying airflow patterns, with computational fluid dynamics confirming drag reductions of up to 4% at higher cruise speeds.
Implementation Method 1
Providing a fairing having a maximum area at a location which is substantially proximal to a location on the upper surface of the aircraft wing at which a shock would be expected to develop without the fairing present is thought to modify the pressure gradients that arise in the vicinity of the junction during flight
Implementation Method 2
One function of such fairings is to reduce or eliminate separation of the airflow in the region of the junction and thereby reduce viscous drag on the aircraft
Data Source
AI summary
A shock control fairing for mounting a junction between adjoining aircraft surfaces. The fairing has a cross-sectional profile which varies along the length of the fairing. The cross-sectional profile of the fairing has a maximum area at a location which, when mounted to an aircraft, is substantially proximal to a location on the surface of the aircraft at which a shock would be expected to develop without the fairing.