Aircraft Gap Sealing Strip with Variable Welting for Drag Reduction

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing sealing solutions for gaps between convexly curved aerodynamic surface elements of aircraft fail to effectively align the neutral fibers of the sealing strip with the surface elements, leading to detrimental bending effects and increased parasitic drag.

Innovation Solution

A sealing strip with reduced or omitted welting sections in specific regions and integrated stringer-type stiffening structures to align the local neutral fibers, ensuring better fit to the curvature of the surface elements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If continuous rigid welting sections are used throughout the sealing strip, then the sealing strip has high structural strength and rigidity, but it cannot properly conform to the curvature of aerodynamic surface elements and creates parasitic drag

Engineering Contradiction:

Improvestructural strengthVSAvoidparasitic drag

Core Design Contradiction:

StrengthVSObject-generated harmful factors

Solution Approach 1:

The sealing strip is divided into multiple longitudinal sections with different welting characteristics. The first and third longitudinal sections have continuous rigid welting sections for structural strength, while the second longitudinal section has discontinuous or reduced welting for flexibility and drag reduction. This segmentation allows each section to perform its specific function optimally.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different sections of the sealing strip are given different local properties: the first and third sections have rigid continuous welting for strength where structural support is needed, while the second section has flexible discontinuous welting for conforming to curvature where aerodynamic performance is critical. This local differentiation resolves the contradiction between overall strength and local flexibility.

Inventive Principle:

Principle #3Local quality

2Stability of the object's composition

If rigid continuous welting sections are used, then the sealing strip maintains structural integrity, but the neutral fiber alignment with aerodynamic surfaces is poor

Engineering Contradiction:

Improvestructural integrityVSAvoidneutral fiber alignment

Core Design Contradiction:

Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The sealing strip structure is segmented into zones with different welting densities. The discontinuous welting in the second longitudinal section allows the neutral fiber to align with the curved aerodynamic surfaces, while the continuous welting in the first and third sections maintains structural integrity at the boundaries.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The welting parameters (continuity, thickness, rigidity) are changed along the longitudinal direction of the sealing strip. By varying these parameters from continuous/rigid in the first section to discontinuous/flexible in the second section, the neutral fiber alignment is optimized for the specific curvature requirements of different aerodynamic surfaces.

Inventive Principle:

Principle #35Parameter changes

3Shape

If the sealing strip is made flexible to conform to curvature, then aerodynamic fit is improved, but structural strength and fixation capability are reduced

Engineering Contradiction:

Improveconformity to curvatureVSAvoidfixation capability

Core Design Contradiction:

ShapeVSStrength

Solution Approach 1:

The sealing strip is segmented into flexible and rigid zones. The second longitudinal section has discontinuous welting that provides flexibility for conforming to curvature, while the first and third sections have continuous welting that provides fixation capability and structural strength where needed.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different local regions of the sealing strip have different mechanical properties tailored to their specific functions. The flexible discontinuous welting region provides shape conformity, while the rigid continuous welting regions provide fixation capability, resolving the contradiction between overall flexibility and local strength.

Inventive Principle:

Principle #3Local quality

Data Source

PatentEP4438466B1Sealing strip, control surface arrangement, aircraft wing and aircraft

Publication Date: 2026.01.14 AIRBUS OPERATIONS GMBH

Figure 1~2
Figure 3~6
Figure 7~9

AI summary

In order to improve a sealing of a gap (20) between control surfaces of an aircraft for enhancing aerodynamics, the invention provides a sealing strip (22) for sealing a gap (20) between convexly curved aerodynamic surface elements (16) of an aircraft (10) such that the sealing strip (22) has a convexly curved outer side (44), the sealing strip (22) having wetting sections (48) at both longitudinal edges of the sealing strip (22) for fixing the sealing strip (22) at the aerodynamic surface elements (16) and a mid-seal section (46) between the wetting sections (48), wherein the wetting sections (48) protrude on an inner side from the mid-seal section (46), wherein the sealing strip (22) has a first length region (102), a second length region (104) and a third length region (106, the second length region (104) being located longitudinally of the sealing strip (22) between the first and third length regions (102, 106), wherein the wetting sections (48) are omitted in the second length region (104) or wherein the wetting sections (48) in the second length region are less rigid than the wetting sections (48) in the first and third length regions (102, 106). Further, a control surface arrangement (14), a wing (12) and an aircraft (10) comprising such a sealing strip (22) as weather seal (24) are described.