Aircraft Cowl Pneumatic Lock Preventing Radial Deformation

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Solution Overview

Problem

The scoop phenomenon in aircraft cowls, where air penetrates under the cowls and reduces aerodynamic performance by increasing drag and fuel consumption, is not effectively addressed by existing solutions that either increase on-board mass or maintenance costs.

Innovation Solution

A pneumatic lock system is integrated into the aircraft nacelle's cowls, allowing a lock to transition between a blocked and free state based on gas pressure variations, preventing radial deformation and scooping, without significantly increasing mass or maintenance costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the number of stiffeners in the cowl is increased to prevent radial deformation and scoop phenomena, then the aerodynamic performance is improved, but the on-board mass increases and fuel consumption increases

Engineering Contradiction:
Improvescoop phenomenonVSAvoidon-board mass
Core Design Contradiction:
Object-affected harmful factorsVSWeight of moving object

Solution Approach 1:

The patent employs a pneumatic lock system where gas pressure variations control a lock mechanism to prevent radial deformation of the cowl. The lock transitions between locked and unlocked states based on pressure changes, providing active control without adding significant structural mass like traditional stiffeners would require.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The invention changes the physical state or parameters of the lock mechanism based on gas pressure. The lock's position (locked/unlocked) is controlled by pressure variations, allowing the system to adapt to different flight conditions and prevent scoop phenomena only when necessary, rather than continuously resisting deformation with heavy structural elements.

Inventive Principle:
Principle #35Parameter changes

2Strength

If traditional locking mechanisms are used at the cowl edge to prevent deformation, then the structural integrity is improved, but the device complexity and maintenance costs increase

Engineering Contradiction:
Improvestructural integrityVSAvoidlocking system complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The pneumatic lock system operates automatically based on gas pressure variations without requiring external control mechanisms or complex actuation systems. The pressure-driven operation simplifies the control architecture while maintaining structural integrity when needed.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

By using gas pressure to drive the lock mechanism, the system replaces complex mechanical or electronic locking systems with a simpler pneumatic actuation system that is easier to maintain and control.

Inventive Principle:
Principle #29Pneumatics and hydraulics

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 pneumatic lock system effectively limits scooping phenomena during flight, maintaining aerodynamic performance while minimizing mass and maintenance costs, thereby reducing fuel consumption.

Implementation Method 1

the passage from one state to another being generated thanks to a variation in the pressure of a gas

Methodology Applied
Scientific EffectGas pressure variation: Pressure Gradient

Data Source

PatentEP2447159B1Aircraft cowl including a means for limiting pneumatic scoop phenomena
Publication Date: 2015.08.12 AIRBUS OPERATIONS (SAS)
  • EP2447159B1 patent drawingFigure 1~2B
  • EP2447159B1 patent drawingFigure 3~5

AI summary

The object of the invention is an aircraft nacelle comprising at its outer wall a hood movable relative to the rest of the nacelle so as to close or unclose an opening, said hood (14) having a hinge relative to the rest of the nacelle and locking/unlocking means distant from the upstream edge (18) of said hood (14) which includes means (19) for limiting the occurrence of scooping phenomena,characterized in that said means (19) for limiting the occurrence of the scooping phenomenon comprise at least one latch (26) integral with the rest of the nacelle or respectively with the hood (14) capable of occupying a so-called blocked state in which a part of the latch (26) interferes with the hood (14) or respectively with the rest of the nacelle and prevents a deformation having a radial component of said hood (14) and another so-called free state in which said part of the latch (26) no longer interferes with the hood (14) or respectively with the rest of the nacelle and allows the opening movement of said hood (14), the transition from one state to the other being generated by a pressure variation of a gas.