Wing Body L-Profile Connection for Laminar Flow

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Solution Overview

Problem

Current wing body designs for commercial aircraft face challenges in maintaining a laminar boundary layer due to shape deviations and rivet connections, which increase friction resistance and require high-lift systems, while also being economically and structurally inefficient for damage repair and weight reduction.

Innovation Solution

A wing body design comprising two components with an integrally formed L-profile that connects internally, avoiding additional mass and surface disturbances, allowing for secure attachment without compromising laminar flow and enabling efficient interchangeability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If rivet connections are used to attach leading edge to wing box, then structural connection is achieved, but surface disturbances occur that promote transition from laminar to turbulent boundary layer

Engineering Contradiction:

Improvestructural connectionVSAvoidsurface disturbances

Core Design Contradiction:

StrengthVSObject-generated harmful factors

Solution Approach 1:

The invention extracts the connecting elements from the flow surface by routing them through the interior space of the wing body components. The leading edge is attached to the wing box using bolts and adhesive that are positioned inside the wing box structure, completely removing visible connection elements from the external flow surface and eliminating their disruptive effect on the boundary layer.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The connection system is moved from the external surface dimension to the internal structure dimension. Instead of attaching components from the outside with visible fasteners, the patent utilizes the interior space of the wing box to position all connecting elements, effectively shifting the connection activity to another spatial dimension that does not interfere with aerodynamic flow.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Object-generated harmful factors

If integral wing design is used, then flow surface is disturbance-free, but damaged leading edge cannot be replaced without replacing entire wing

Engineering Contradiction:

Improveflow surface qualityVSAvoidcomponent replaceability

Core Design Contradiction:

Object-generated harmful factorsVSEase of repair

Solution Approach 1:

The wing body is divided into separate replaceable components - specifically the leading edge can be detached and replaced independently from the wing box. The connection system using interior-mounted bolts and adhesive allows the leading edge to be segmented as a separate module that can be removed and replaced without affecting the entire wing structure, while maintaining a smooth flow surface at the junction.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention introduces an intermediary connection system consisting of bolts and adhesive positioned in the interior space that mediates between the need for structural connection and the requirement for component replaceability. This intermediary mechanism allows individual components to be detached and reattached, enabling repair without compromising the overall structural integrity or flow surface quality.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Strength

If conventional riveted connection is used, then structural attachment is achieved, but additional mass is introduced and laminar flow is disrupted

Engineering Contradiction:

Improvestructural attachmentVSAvoidwing body weight

Core Design Contradiction:

StrengthVSWeight of moving object

Solution Approach 1:

The invention partially replaces the mechanical rivet system with an adhesive bonding system. In addition to interior-mounted bolts, adhesive is applied between the leading edge and wing box surfaces to provide structural attachment. This substitution reduces the need for extensive mechanical fastening, thereby reducing the overall mass of the connection system while maintaining attachment strength.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

4Force

If high-lift systems with extendable slats are used, then lift generation is improved, but gaps and steps are created that prevent laminar boundary layer formation

Engineering Contradiction:

Improvelift generationVSAvoidboundary layer disruption

Core Design Contradiction:

ForceVSObject-generated harmful factors

Solution Approach 1:

Instead of extending slats forward from the leading edge (conventional approach), the patent inverts the approach by deploying flaps backward from the trailing edge of the leading edge. This inverted high-lift system generates the necessary lift forces without creating gaps or steps on the upper surface of the leading edge, thereby preserving laminar boundary layer formation while still achieving enhanced lift capability.

Inventive Principle:

Principle #13The other way round (Inversion)

Data Source

PatentEP3078587B1Wing body

Publication Date: 2021.08.25 DEUTSCHES ZENTRUM FÜR LUFT UND RAUMFAHRT E V

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AI summary

The invention relates to a wing body (10) for flying objects comprising at least two wing body components (11, 12), each of which has a flowable surface on an outer side and forms an interior space on an inner side, separated from the outer side. According to the invention, an L-profile (20) projecting into the interior space is provided on the first wing body component (11), which is integrally formed with the first wing body component (11) and can be arranged on an L-profile receptacle (30) of the second wing body component (12).