Upstream Inlet Vane Layout for Low-Speed Aircraft Inlet Flow

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Solution Overview

Problem

Existing propulsion system arrangements for aircraft face challenges in managing boundary layer tripping and vortex formation during low-speed operations, leading to inefficiencies and potential airflow disruptions.

Innovation Solution

Incorporation of inlet vanes positioned upstream of the propulsion system to modify boundary layer airflow and redirect tripped air into a wing top surface flow gully, reducing vortex formation and enhancing airflow stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the propulsion system is positioned with the airflow inlet spaced vertically out from the airframe structure, then the propulsion system can be effectively mounted and operated, but boundary layer tripping and vortex formation occur during low-speed operations causing airflow disruptions

Engineering Contradiction:
Improveairflow stabilityVSAvoidvortex formation
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The inlet vane acts as an intermediary element positioned between the airframe structure and the propulsion system airflow inlet. It modifies the boundary layer airflow by redirecting tripped air into the wing top surface flow gully, preventing vortex formation and maintaining laminar flow characteristics into the propulsion system inlet.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The inlet vane extracts and redirects the problematic boundary layer air that has been tripped by the propulsion system mounting structure. By channeling this air into the flow gully region, the vane removes the harmful effect of boundary layer tripping from the main airflow path entering the propulsion system.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If inlet vanes are added to manage boundary layer airflow, then vortex formation is reduced and airflow stability is improved, but the device complexity increases

Engineering Contradiction:
Improveairflow stabilityVSAvoidpropulsion system structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The inlet vane serves multiple functions simultaneously: it acts as a flow redirector for boundary layer air, provides structural support for the propulsion system mounting, and contributes to the overall aerodynamic shaping of the airframe. This multi-functionality reduces the need for additional separate components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The inlet vane is integrated with the wing top surface flow gully structure, combining the flow management function with the existing airframe geometry. This merging approach allows the vane to utilize the natural flow path created by the airframe structure rather than requiring completely separate flow management components.

Inventive Principle:
Principle #5Merging (Combining)

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 inlet vanes effectively manage airflow during low-speed conditions, minimizing vortex formation and improving propulsion system efficiency by maintaining laminar flow over the aircraft surface.

Implementation Method 1

manage boundary layer tripping and vortex formation during low-speed operations

Methodology Applied
Scientific EffectBoundary layer: Boundary Layer

Implementation Method 2

manage boundary layer tripping and vortex formation during low-speed operations

Methodology Applied
Scientific EffectVortex formation: Vortex Ring

Implementation Method 3

maintaining laminar flow over the aircraft surface

Methodology Applied
Scientific EffectLaminar flow: Laminar Flow

Data Source

PatentEP4707175A1Inlet vane forward of aircraft propulsion system airflow inlet
Publication Date: 2026.03.11 RTX CORP
  • EP4707175A1 patent drawingFigure 1
  • EP4707175A1 patent drawingFigure 2
  • EP4707175A1 patent drawingFigure 3

AI summary

An assembly is provided for an aircraft (20). This aircraft assembly includes an airframe structure (98), a propulsion system (24) and a vane (30). The airframe structure (98) includes a fuselage (26) and at least two wings (28A, 28B). The fuselage (26) extends longitudinally along a longitudinal centerline (34) from a forward end (36) of the fuselage (26) to an aft end (38) of the fuselage (26). The wings (28A, 28B) extend laterally from opposing sides (44A, 44B) of the fuselage (26). The propulsion system (24) is mounted to the airframe structure (98). The propulsion system (24) includes an airflow inlet (106) into the propulsion system (24). The airflow inlet (106) is spaced vertically out from a top side (42) of the airframe structure (98). The vane (30) projects vertically out from the top side (42) of the airframe structure (98) to a distal end (116) of the vane (30). The vane (30) laterally overlaps and is longitudinally forward of the airflow inlet (106).