Aircraft Air Intake Butt-Weld Layout for Longer Laminar Flow

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Solution Overview

Problem

The existing air inlets of aircraft nacelles suffer from increased drag and energy consumption due to the presence of connecting elements that disrupt the laminar air flow, reducing the length over which the air flow remains laminar and thus increasing aerodynamic resistance.

Innovation Solution

The introduction of an intermediate panel with a first butt weld bead connecting the lip and exterior panel, and a second connection between the intermediate and exterior panels, separated from the leading edge by a distance greater than or equal to the laminar air flow length, maintains the laminar exterior air flow and reduces drag and energy consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If connecting elements (screws, rivets) are used to join the lip and outer panel, then the structural connection is achieved, but the laminar air flow is disrupted and drag increases

Engineering Contradiction:
Improvestructural connectionVSAvoiddrag
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The invention removes the harmful connecting elements (screws, rivets) from the air flow path by using a monolithic lip structure without discrete fasteners. The lip is formed as a single continuous piece that connects to the outer panel through integrated joints, eliminating the need for separate connecting elements that would disrupt the laminar flow and generate drag.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention merges the lip and outer panel into an integrated structure where the connecting elements are incorporated within the joint design itself rather than being separate components. The lip and outer panel are joined through a continuous connection that maintains the smooth aerodynamic surface, combining structural integrity with aerodynamic efficiency.

Inventive Principle:
Principle #5Merging (Combining)

2Ease of manufacture

If connecting elements are placed close to the leading edge for easier assembly, then assembly ease is improved, but the laminar flow length is reduced and energy consumption increases

Engineering Contradiction:
Improveassembly easeVSAvoidenergy consumption
Core Design Contradiction:
Ease of manufactureVSUse of energy by moving object

Solution Approach 1:

The invention segments the air inlet structure into distinct modular components (lip, outer panel, intermediate panel) that can be manufactured and assembled separately. The lip is designed as a standalone component with integrated connection features that allow for easy assembly while maintaining aerodynamic performance, as the modular design enables pre-assembly and quality control before final installation.

Inventive Principle:
Principle #1Segmentation

3Object-affected harmful factors

If the lip is designed as a monolithic structure without connecting elements, then laminar flow is maintained, but structural connection and assembly become more difficult

Engineering Contradiction:
Improvelaminar flow maintenanceVSAvoidassembly complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The invention employs a nested structure where the intermediate panel is positioned between the lip and outer panel, creating a layered assembly. The connecting elements are nested within the joint regions, and the intermediate panel provides a mounting surface for additional components. This nested arrangement allows for systematic assembly while maintaining the smooth external surfaces needed for laminar flow.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The intermediate panel serves as an intermediary component between the lip and outer panel, facilitating their connection. This intermediate element provides a stable mounting surface for connecting elements and allows for precise positioning and alignment, simplifying the assembly process while maintaining the aerodynamic integrity of the overall structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

This configuration allows for a longer laminar air flow, thereby reducing drag and energy consumption of the aircraft by minimizing disturbances to the air flow, enhancing the aerodynamic efficiency of the air inlet.

Implementation Method 1

The first connection, which connects the first edge of the intermediate panel and the lip, comprises at least a first butt weld bead

Methodology Applied
Scientific EffectWelding: Welding

Implementation Method 2

an outer airflow which is laminar over a given length

Methodology Applied
Scientific EffectLaminar flow: Laminar Flow

Data Source

PatentEP4410669A1Aircraft air intake comprising at least two walls joined together by welding, method for assembling such an air intake and aircraft comprising at least one such air intake
Publication Date: 2024.08.07 AIRBUS OPERATIONS (SAS)
  • EP4410669A1 patent drawingFigure 1~2
  • EP4410669A1 patent drawingFigure 3~4
  • EP4410669A1 patent drawingFigure 5~6

AI summary

The invention relates to an air inlet for an aircraft nacelle comprising: - a lip (42) having a leading edge (44.1) configured to split an airflow (46) into internal and external airflows (46.1, 46.2), the internal airflow (46.1) entering the air inlet (40), - an outer panel (48), - an intermediate panel (54), interposed between the lip (42) and the outer panel (48), having a first edge (54.1) connected to the lip (42) by at least one first connection (56.1) and a second edge (54.2) connected to the outer panel (48) by at least one second connection (56.2), the first connection (56.1) linking the first edge (54.1) of the intermediate panel (54) and the lip (42) comprising at least one butt weld bead at the end (60) which has an external face (F60) in line with the external faces (F42, F54) of the lip (42) and the intermediate panel (54).