Multicavity Combustor Damper for Multi-Frequency Instability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing acoustic dampers in turbine engines are limited to targeting a single frequency of instability, failing to effectively suppress multi-tonal combustion instability, which can damage equipment.
Innovation Solution
The implementation of a multicavity damper with multiple cavity volumes of unique lengths, allowing for customized acoustic attenuation characteristics to target and damp multiple frequencies, including both low and high frequency tones, thereby broadening the range of frequencies damped.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single-cavity damper is used, then the device complexity is low, but the frequency coverage is limited to a single target frequency
Solution Approach 1:
The damper is divided into multiple cavities (first cavity and second cavity) with different lengths, where each cavity targets a specific frequency range. This segmentation allows the damper to cover multiple frequencies simultaneously while maintaining a relatively simple overall structure compared to using multiple separate dampers.
Solution Approach 2:
The multicavity damper performs multiple functions by targeting and dampening multiple frequency ranges (low frequency and high frequency tones) within a single device. The first cavity targets lower frequencies while the second cavity targets higher frequencies, making the damper universally applicable to multi-tonal combustion instabilities.
2Adaptability or versatility
If multiple separate dampers are used to target different frequencies, then the frequency coverage is broad, but the device complexity and space requirement increase
Solution Approach 1:
Multiple damper cavities are merged into a single integrated damper assembly that communicates with the combustion chamber through one common opening. This combining approach achieves multi-frequency damping capability while occupying less space than multiple separate dampers would require, as the cavities share common walls and structure.
3Adaptability or versatility
If a multicavity damper with multiple opening is used, then the frequency coverage is broad, but the number of openings in the combustion liner increases
Solution Approach 1:
Multiple cavities are designed to communicate with the combustion chamber through a single common opening in the combustion liner, rather than each cavity having its own separate opening. This merging of openings reduces the number of penetrations in the combustion liner while still allowing each cavity to function independently for targeting different frequencies.
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 multicavity damper effectively suppresses multi-tonal combustion instability by targeting discrete frequencies and broadening the frequency band of damping, enhancing the acoustic performance and reducing equipment damage.
Implementation Method 1
The multicavity damper includes a first cavity volume and a second cavity volume, each cavity volume having a different length. The different cavity lengths allow the damper to target and damp multiple discrete frequencies simultaneously through acoustic resonance mechanisms.
Implementation Method 2
a multicavity damper in fluid communication with the combustion chamber to dampen an instability generated in the combustion chamber by the combustion products
Data Source
AI summary
A gas turbine engine includes a compressor section for compressing air flowing therethrough to provide a compressed air flow, a combustor including a combustion chamber, the combustion chamber configured to combust a mixture of a fuel flow and the compressed air flow to generate combustion products, and a turbine section having at least one turbine driven by the combustion products. The gas turbine engine includes a multicavity damper in fluid communication with the combustion chamber to dampen an instability generated in the combustion chamber by the combustion products. The multicavity damper has a plurality of cavity volumes and the length of each cavity volume is different.