Aircraft Engine Air Inlet Elevation for Boundary-Layer Deflection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing aircraft designs struggle to supply jet engines with high-energy air, which is necessary for high performance and maneuverability, particularly in supersonic aircraft.

Innovation Solution

An aircraft structure featuring a fuselage, wing, and an air inlet with an elevation that deflects low-energy boundary layer fluid away from the inlet, using a multiply curved contour line that extends asymmetrically with respect to the angle bisector between the wing and fuselage, and a housing surrounding the elevation to form an opening for high-energy air intake.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a conventional air inlet is used without an elevation, then the structure is simple, but low-energy boundary layer fluid is ingested into the engine inlet

Engineering Contradiction:
Improveenergy of air intakeVSAvoidcomplexity of air inlet structure
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The air inlet structure is segmented into distinct functional zones: the elevation (bump) structure that deflects boundary layer fluid, the housing that surrounds the elevation, and the opening that receives high-energy air. This segmentation allows each component to perform its specific function optimally while maintaining overall system effectiveness.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The elevation acts as an intermediary element between the boundary layer fluid and the air inlet opening. It mediates the interaction by deflecting the low-energy boundary layer fluid away from the opening, thereby protecting the engine inlet from ingesting low-energy air while allowing high-energy air to be captured.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of energy

If the elevation is positioned symmetrically, then the manufacturing is simpler, but the deflection of boundary layer fluid is less effective

Engineering Contradiction:
Improveenergy of air intakeVSAvoidprecision of elevation positioning
Core Design Contradiction:
Loss of energyVSManufacturing precision

Solution Approach 1:

The elevation is deliberately positioned asymmetrically with respect to the angle bisector of the angle between the wing and fuselage. This asymmetric positioning optimizes the deflection of boundary layer fluid away from the air inlet opening, improving the effectiveness of boundary layer diversion and enhancing the energy quality of the air intake.

Inventive Principle:
Principle #4Asymmetry

3Force

If the leading edge of the wing is positioned further forward, then the lift at high angles of attack is improved, but the air inlet may ingest more boundary layer fluid

Engineering Contradiction:
Improvelift at high angles of attackVSAvoidenergy of air intake
Core Design Contradiction:
ForceVSLoss of energy

Solution Approach 1:

The elevation is positioned in advance (upstream) of the air inlet opening to preemptively deflect the boundary layer fluid away from the inlet. This preliminary action ensures that when high-energy air is captured, the boundary layer fluid has already been diverted, preventing contamination of the engine inlet even when the wing leading edge is positioned forward for enhanced lift.

Inventive Principle:
Principle #10Preliminary action

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 enhances the energy of the air intake, improving jet engine performance and aircraft maneuverability by deflecting low-energy boundary layer fluid, allowing more lift at high angles of attack.

Implementation Method 1

the boundary layer of the flow, which is generated on the outer skin of the aircraft

Methodology Applied
Scientific EffectBoundary layer: Boundary Layer

Implementation Method 2

the elevation is configured to deflect, from an opening of the air inlet, a boundary layer fluid

Methodology Applied
Scientific EffectFlow deflection:

Data Source

PatentEP3871980B1Aircraft structure having an inlet opening for engine air
Publication Date: 2025.08.13 AIRBUS DEFENCE & SPACE GMBH
  • EP3871980B1 patent drawingFigure 1
  • EP3871980B1 patent drawingFigure 2~3
  • EP3871980B1 patent drawingFigure 4~5

AI summary

What is described is an aircraft structure (10) having a fuselage (20), a wing (30) and an air inlet (100) for receiving air for an engine (70). The air inlet (100) contains an elevation (120) which rises from the fuselage (20) and the wing (30). The elevation (120) is arranged in a transition region between the wing (30) and the fuselage (20) and extends asymmetrically with respect to an angle bisector of an angle between a surface of the wing and the lateral surface of the fuselage. By virtue of this construction, a leading edge of the wing can be arranged further forward than the air inlet, and the air inlet configured according to these principles can positively influence a flow boundary layer on the aircraft structure.