Combustor Damper Combining Quarter-Wave and Helmholtz Resonance

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Solution Overview

Problem

Turbine engines experience combustion instability, which manifests as sinusoidal pressure with significant amplitude, potentially damaging equipment, and existing acoustic dampers struggle to effectively target and damp multiple frequencies simultaneously.

Innovation Solution

The integration of a damper that combines a quarter wave tube with a Helmholtz resonator, allowing for customizable acoustic attenuation characteristics, capable of targeting and damping both low and high frequency tones, and broadening the attenuation curve to capture multi-tonal behavior in the combustor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If existing acoustic dampers are used, then single frequency damping is achieved, but multiple frequencies cannot be targeted simultaneously

Engineering Contradiction:

Improvefrequency targeting capabilityVSAvoiddamper structure

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines a quarter wave tube and a Helmholtz resonator into a single integrated damper structure. The quarter wave tube portion targets specific frequencies through its length and configuration, while the Helmholtz resonator portion targets different frequencies through its cavity volume and neck dimensions. This merging allows the damper to effectively target multiple combustion instability frequencies simultaneously without requiring separate dampers for each frequency.

Inventive Principle:

Principle #5Merging (Combining)

2Force

If a quarter wave tube is used, then high frequency damping is achieved, but low frequency damping is limited

Engineering Contradiction:

Improveacoustic attenuationVSAvoidfrequency range coverage

Core Design Contradiction:

ForceVSAdaptability or versatility

Solution Approach 1:

The damper is segmented into two distinct functional portions: a quarter wave tube portion and a Helmholtz resonator portion. Each segment is optimized for different frequency ranges - the quarter wave tube for high frequencies and the Helmholtz resonator for low frequencies. This segmentation allows each portion to specialize in damping specific frequency ranges while working together to provide broad-spectrum attenuation.

Inventive Principle:

Principle #1Segmentation

3Force

If a Helmholtz resonator is used, then low frequency damping is achieved, but high frequency damping is limited

Engineering Contradiction:

Improveacoustic attenuationVSAvoidfrequency range coverage

Core Design Contradiction:

ForceVSAdaptability or versatility

Solution Approach 1:

Inventive Principle:

Principle #1Segmentation

4Adaptability or versatility

If the damper volume expansion angle is increased, then the attenuation curve is broadened, but the damper size increases

Engineering Contradiction:

Improveattenuation curve broadeningVSAvoiddamper volume

Core Design Contradiction:

Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The patent utilizes parameter changes in the damper volume expansion angle to optimize the attenuation curve broadening. By adjusting the expansion angle of the damper volume, the attenuation characteristics can be tuned to target specific frequency ranges more effectively. This parameter optimization allows for achieving broad attenuation coverage while minimizing the overall damper volume required.

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

The damper effectively dampens combustion instability across a wide frequency range, improving engine operability, durability, and reducing emissions by customizing acoustic attenuation to suit specific combustion system needs.

Implementation Method 1

The integration of a damper that combines a quarter wave tube with a Helmholtz resonator, allowing for customizable acoustic attenuation characteristics

Methodology Applied

Scientific EffectQuarter-wave resonance: Resonance

Implementation Method 2

The integration of a damper that combines a quarter wave tube with a Helmholtz resonator, allowing for customizable acoustic attenuation characteristics

Methodology Applied

Scientific EffectHelmholtz resonance: Helmholtz Resonance

Data Source

PatentEP4650662A1Turbine engine having a damper

Publication Date: 2025.11.19 GENERAL ELECTRIC CO

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AI summary

A gas turbine engine (10) having a compressor section (22) for compressing air (64) flowing therethrough to provide a compressed air flow (236), a combustor (200) including a combustion chamber (216), the combustion chamber (216) configured to combust a mixture of a fuel flow and the compressed air flow (236) to generate combustion products, a turbine section (30) having at least one turbine driven by the combustion products, and a damper (250, 300, 400, 600) in fluid communication with the combustion chamber (216) to dampen an instability generated in the combustion chamber (216) by the combustion products. The damper (250, 300, 400, 600) defined by nds ∝ nfp, ap ∝ dpn, and ab ∝ dpv * dpvea, where nds is a number of damper cavities (304, 404, 608, 612) in series, nfp is a number of discrete frequencies to be damped, ap is an acoustic damping potential, dpn is a neck open area ratio, ab is an acoustic damping broadness, dpv is a damper volume, and dpvea is a damper volume expansion angle.