Tail Cone Generator Acoustic Suppression via Nested Panels

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Solution Overview

Problem

Conventional gas turbine engines face challenges in integrating electric generators due to space constraints and the harsh environment around the tail cone, where high temperatures and noise complicate the placement of generators driven by low pressure spools.

Innovation Solution

The integration of an electric generator within the tail cone, operably connected to the low speed spool, and the use of acoustic panel assemblies comprising an acoustic backing sheet, an outer porous liner, and an acoustic liner to mitigate noise, along with a structural support housing and mounting system to secure the tail cone, allowing for the use of lighter ceramic materials.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If an electric generator is integrated within the tail cone to utilize available space, then space utilization is improved, but the generator is exposed to high temperatures and noise which worsens the operating environment

Engineering Contradiction:

Improvespace utilizationVSAvoidhigh temperature and noise exposure

Core Design Contradiction:

Volume of moving objectVSObject-affected harmful factors

Solution Approach 1:

The electric generator is nested within the tail cone structure, utilizing the available space inside the tail cone. The generator is positioned within the hollow interior space of the tail cone, effectively using otherwise empty volume while remaining protected by the tail cone structure against high temperatures and noise

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The tail cone acts as an intermediary structure between the noisy, high-temperature engine environment and the electric generator. It provides a protective barrier that shields the generator from harmful thermal and acoustic conditions while allowing the generator to operate within the confined space

Inventive Principle:

Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If acoustic panel assemblies are added around the generator to reduce noise, then noise reduction is improved, but device complexity increases

Engineering Contradiction:

Improvenoise levelVSAvoidstructural complexity

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

Acoustic panel assemblies are installed around the electric generator within the tail cone. These panels form a flexible acoustic barrier that absorbs and dampens noise generated by the generator, creating a quieter operating environment without requiring a complete structural redesign

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The acoustic treatment is segmented into discrete panel assemblies that can be individually installed around the generator. This modular approach allows noise reduction to be achieved through add-on components rather than redesigning the entire tail cone structure, managing complexity through modularity

Inventive Principle:

Principle #1Segmentation

3Weight of moving object

If ceramic materials are used for the tail cone to reduce weight and increase temperature resistance, then weight and temperature resistance are improved, but manufacturing difficulty increases

Engineering Contradiction:

Improvetail cone weightVSAvoidmanufacturing ease

Core Design Contradiction:

Weight of moving objectVSEase of manufacture

Solution Approach 1:

The tail cone is constructed from ceramic matrix composite (CMC) material, which combines the high-temperature resistance and weight reduction benefits of ceramics with improved manufacturability compared to monolithic ceramics. The composite structure allows for more feasible manufacturing processes while maintaining the desired weight and thermal properties

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The material composition of the tail cone is changed from conventional metals to ceramic materials, fundamentally altering the density and temperature resistance parameters. This material substitution achieves weight reduction and enhanced thermal performance, with the CMC variant specifically addressing manufacturing challenges

Inventive Principle:

Principle #35Parameter changes

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 effectively utilizes otherwise empty space in the tail cone, provides a noise-reducing environment for the generator, and allows for the use of lighter, high-temperature-resistant ceramic materials, enhancing the engine's efficiency and structural integrity.

Implementation Method 1

one or more acoustic panel assemblies located around the electric generator, the one or more acoustic panel assemblies including: an acoustic backing sheet, an outer porous liner, and an acoustic liner interposed between the outer porous liner and the acoustic backing sheet

Methodology Applied

Scientific EffectAcoustic absorption: Acoustic Absorption

Data Source

PatentUS11434778B2Integrated tail cone and mounted generator acoustic suppression

Publication Date: 2022.09.06 HAMILTON SUNDSTRAND CORP

AI summary

A gas turbine engine including: a tail cone; a low pressure compressor; a low pressure turbine; a low speed spool interconnecting the low pressure compressor and the low pressure turbine; and an electric generator located within the tail cone, the electric generator being operably connected to the low speed spool; and one or more acoustic panel assemblies located around the electric generator, the one or more acoustic panel assemblies including: an acoustic backing sheet, an outer porous liner, and an acoustic liner interposed between the outer porous liner and the acoustic backing sheet.