Flexible Heat Shield Assembly for Aircraft Strut Thermal Protection

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Solution Overview

Problem

Existing heat shield technologies for aircraft engine struts fail to effectively manage high temperatures while maintaining aerodynamic efficiency and structural integrity, leading to potential heat degradation and increased drag.

Innovation Solution

A heat shield assembly with a flexible member that allows thermal expansion and is mounted to the strut with frame members and mounting structures, enabling the heat shield to change shape in response to temperature changes while maintaining aerodynamic curvature and reducing drag.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a rigid heat shield is used to protect the strut from heat degradation, then thermal protection is improved, but the heat shield cannot accommodate thermal expansion and may deform or fail under temperature changes

Engineering Contradiction:
Improveheat protectionVSAvoidstructural integrity under thermal cycling
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The heat shield employs a flexible membrane structure that can expand and contract in response to temperature changes. The membrane is supported by a framework that allows it to maintain its protective function while accommodating thermal deformation, preventing structural failure during thermal cycling.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The heat shield transitions from a static rigid structure to a dynamic flexible structure that can adapt its shape and volume in response to thermal conditions. The flexible membrane allows the heat shield to dynamically adjust to thermal expansion and contraction, maintaining reliability under temperature variations.

Inventive Principle:
Principle #15Dynamics

2Temperature

If a large heat shield is used to provide adequate thermal protection, then heat degradation prevention is improved, but drag increases due to larger wetted surface area

Engineering Contradiction:
Improvethermal protection coverageVSAvoidaerodynamic drag
Core Design Contradiction:
TemperatureVSObject-generated harmful factors

Solution Approach 1:

The heat shield uses a flexible membrane that can dynamically adjust its surface area and shape. When thermal protection is needed, the membrane expands to cover the required area; when not needed, it can be reduced or reconfigured to minimize drag, allowing the system to optimize both thermal protection and aerodynamic performance.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The heat shield's physical parameters such as surface area, volume, and shape are made variable through the flexible membrane structure. This allows the heat shield to change its effective size and configuration based on operational requirements, providing adequate thermal protection only when and where needed, thereby reducing overall drag.

Inventive Principle:
Principle #35Parameter changes

3Stability of the object's composition

If complex mounting structures are used to securely attach the heat shield to the strut, then structural stability is improved, but maintenance access becomes difficult

Engineering Contradiction:
Improveheat shield attachment stabilityVSAvoidmaintenance accessibility
Core Design Contradiction:
Stability of the object's compositionVSEase of repair

Solution Approach 1:

The heat shield system is divided into modular components including the flexible membrane, support framework, and simplified mounting structures. This segmentation allows individual components to be easily accessed, inspected, and replaced during maintenance while maintaining stable attachment when properly assembled.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of using complex mounting structures that enclose or obscure the heat shield, the invention employs simplified attachment mechanisms that expose the heat shield components. This inversion of the mounting approach makes the heat shield more accessible for maintenance while still providing stable attachment through the framework support.

Inventive Principle:
Principle #13The other way round (Inversion)

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 flexible heat shield assembly effectively protects the strut and wing from heat degradation, reduces drag by minimizing the wetted surface area, and improves maintenance access, while maintaining structural integrity and aerodynamic efficiency.

Implementation Method 1

The heat shield assembly includes flexible member with freedom of movement to allow thermal expansion

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

a heat shield may be provided over at least an area of the strut close to the hot exhaust to prevent heat degradation of the strut

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentEP3546340B1Heat shield assembly and mounting thereof on aircraft
Publication Date: 2020.12.16 THE BOEING CO
  • EP3546340B1 patent drawingFigure 1
  • EP3546340B1 patent drawingFigure 2
  • EP3546340B1 patent drawingFigure 3

AI summary

Various techniques provide a heat shield assembly and mounting thereof on an aircraft. In one example, a heat shield assembly may include flexible member. The heat shield assembly may further include a plurality of frame members disposed on the flexible member. The heat shield assembly may further include a plurality of mounting structures configured to directly mount the heat shield assembly to a strut of an airplane. Each of the plurality of mounting structures may be disposed on one of the plurality of frame members. Related methods are also provided.