Modular Acoustic Blocks for Gas Turbine Noise Reduction

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Solution Overview

Problem

Conventional acoustic liners for gas turbine engines are costly and inefficient due to the need for thicker or longer materials to effectively dampen sound frequencies, which increases the engine's footprint and pressure drop, and are difficult to modify once installed.

Innovation Solution

The use of uniformly configured modular acoustic blocks with varying interior cavity lengths to target specific sound frequencies, allowing for efficient assembly and minimal thickness to reduce noise while minimizing pressure loss and cost.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If thicker acoustic liners are used to dampen sound frequencies, then noise reduction is improved, but pressure drop increases and engine efficiency deteriorates

Engineering Contradiction:

Improvenoise reductionVSAvoidpressure drop

Core Design Contradiction:

Object-affected harmful factorsVSLoss of energy

Solution Approach 1:

The acoustic liner is divided into multiple discrete blocks, each containing multiple cavities of different lengths. This segmentation allows different cavity lengths to target different sound frequencies independently, achieving broad-spectrum noise reduction without requiring uniform thickness throughout the entire liner structure.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Each block contains cavities with specifically tailored lengths (e.g., first, second, and third cavity lengths) designed to dampen specific frequency ranges. This local customization of cavity dimensions allows the liner to be acoustically optimized for particular frequency bands while maintaining minimal overall thickness to reduce pressure drop.

Inventive Principle:

Principle #3Local quality

2Object-affected harmful factors

If longer acoustic liners are used to dampen sound frequencies, then noise reduction is improved, but engine footprint increases and cost increases

Engineering Contradiction:

Improvenoise reductionVSAvoidengine footprint

Core Design Contradiction:

Object-affected harmful factorsVSLength of stationary object

Solution Approach 1:

The invention transitions from extending acoustic liner length along the exhaust flow direction to achieving noise reduction through variations in cavity depth (thickness dimension) and cavity length (internal dimension). Multiple cavity lengths within each block enable broad frequency damping without increasing the external footprint of the liner assembly.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Object-affected harmful factors

If conventional acoustic liners are used, then noise reduction is achieved, but modification and construction difficulty increases after installation

Engineering Contradiction:

Improvenoise reductionVSAvoidmodification difficulty

Core Design Contradiction:

Object-affected harmful factorsVSEase of repair

Solution Approach 1:

The acoustic liner is constructed from separate, modular blocks that can be independently installed, removed, or replaced. This modular segmentation enables easy modification of specific frequency targets by swapping individual blocks without requiring to dismantle the entire liner assembly, significantly improving maintainability and adaptability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The modular block design allows the acoustic liner configuration to be dynamically adjusted over time. Different blocks with varying cavity configurations can be installed or removed based on changing noise requirements, enabling the system to adapt to different operational conditions without permanent fixed installation.

Inventive Principle:

Principle #15Dynamics

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 modular acoustic blocks effectively absorb a broad range of sound frequencies with minimal thickness, reducing the overall length and cost of the acoustic liner, and can be easily assembled or modified to optimize noise reduction in gas turbine engines.

Implementation Method 1

The interior cavities may have lengths that are varied across a range of lengths for dampening a targeted range of sound frequencies

Methodology Applied

Scientific EffectAcoustic absorption: Acoustic Absorption

Data Source

PatentUS10815894B2Modular acoustic blocks and acoustic liners constructed therefrom

Publication Date: 2020.10.27 GE INFRASTRUCTURE TECH LLC

AI summary

An exhaust processing system that includes: an exhaust passageway for directing exhaust gases, the exhaust passageway having passageway walls that define and enclose the exhaust passageway between an upstream position and a downstream position; and an acoustic liner formed against and covering at least one of the passageway walls of the exhaust passageway. The acoustic liner may include uniformly configured modular acoustic blocks fitted against each other. The modular acoustic blocks each may include interior cavities having different lengths configured to dampen targeted sound frequencies.