Aircraft Nacelle Shield for Impact Energy Absorption

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional aircraft propulsion nacelle structures are heavy and costly due to the need for robust front frames to absorb impact energy from bird strikes and external objects, which compromises their structural stiffness and manufacturing efficiency.

Innovation Solution

Incorporating an annular shield positioned in front of the stiffening frame, allowing it to deform during impacts and absorb energy, thereby protecting the stiffening frame and reducing the need for it to absorb impact energy, allowing for a lighter and more flexible frame configuration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the stiffening frame is designed to absorb impact energy from bird strikes and external objects, then the nacelle's resistance to external impacts is improved, but the weight and manufacturing cost of the nacelle increase

Engineering Contradiction:

Improveresistance to external impactsVSAvoidweight of the nacelle

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The patent divides the impact energy absorption function into two separate components: the deformable shield that absorbs the majority of impact energy, and the stiffening frame that provides structural support. This segmentation allows the stiffening frame to be lighter since it no longer needs to be oversized for impact absorption, while the shield specifically handles the impact protection function.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The deformable shield acts as an intermediary element positioned between the external impact source and the stiffening frame. It absorbs the harmful impact energy through controlled deformation, protecting the stiffening frame from direct impact forces, thereby allowing the frame to be optimized for stiffness rather than impact absorption.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If the stiffening frame is designed to absorb impact energy from bird strikes and external objects, then the nacelle's resistance to external impacts is improved, but the manufacturing cost of the nacelle increases

Engineering Contradiction:

Improveresistance to external impactsVSAvoidmanufacturing cost of the nacelle

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent segments the impact protection system into a dedicated deformable shield component and a lighter stiffening frame. This allows for more efficient manufacturing as each component can be optimized independently - the shield for energy absorption and the frame for structural support - rather than requiring an oversized frame to perform both functions simultaneously.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The deformable shield is designed as a sacrificial element that absorbs impact energy through controlled deformation or failure. This disposable component protects the more expensive and critical stiffening frame, allowing the frame to be manufactured with lower safety margins and reduced cost.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Reliability

If the stiffening frame is made heavier to absorb impact energy, then the nacelle's resistance to external impacts is improved, but the structural stiffness of the nacelle is compromised

Engineering Contradiction:

Improveresistance to external impactsVSAvoidstructural stiffness of the nacelle

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The patent separates the impact absorption function (performed by the deformable shield) from the structural stiffness function (performed by the stiffening frame). This allows the frame to be optimized specifically for maintaining structural stiffness without the penalty of added weight from impact absorption capabilities, while the shield provides the necessary impact resistance.

Inventive Principle:

Principle #1Segmentation

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 resistance to external impacts without increasing the weight or manufacturing costs of the nacelle, allowing for a lighter and more efficient structural design that maintains structural integrity and reduces drag.

Implementation Method 1

allowing deformation of the shield upon impact of an external object entering through the air inlet lip and striking the shield, so as to absorb all or part of the impact energy

Methodology Applied

Scientific EffectDeformation: Deformation

Data Source

PatentEP3772458B1Forward section of nacelle of an aircraft propulsion assembly comprising a shield in front of its stiffening frame

Publication Date: 2022.06.22 AIRBUS OPERATIONS (SAS)

Figure 1~2
Figure 3~4
Figure 5~6

AI summary

The invention relates to a forward portion of an aircraft propulsion unit nacelle. An annular stiffening frame (5) about a longitudinal axis (A) of nacelle extension is disposed at the rear end of the forward portion (P1). An annular shield (6) is positioned in front of the stiffening frame (5) and connects an inner peripheral edge (51) of the stiffening frame (5) to an internal structure (3). The shield includes a portion extending towards the outer panel (4) beyond the inner peripheral edge (51) of the stiffening frame, said portion forming a non-zero angle with respect to said stiffening frame (5) so as to provide a free space (8) with respect to said stiffening frame (5) at the rear of said portion.The shield can thus deform upon impact from an external object entering through the air intake lip (1), without the stiffening frame itself being deformed, thereby absorbing all or part of the impact energy. The invention also relates to a nacelle comprising such a front portion and to an aircraft comprising such a nacelle.