Variable Bleed Valve Assemblies With Acoustic Black Hole Damping

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Turbine engines experience compressor instabilities and mechanical vibrations due to acoustic resonance in variable bleed valve cavities, leading to potential damage and performance issues during low-speed operations.

Innovation Solution

Incorporation of an acoustic black hole assembly within the variable bleed valve to absorb and dissipate acoustic energy, reducing resonant frequencies and vibrations in the VBV cavity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the variable bleed valve cavity is closed during low-speed operations, then the valve can control bleed flow, but acoustic resonance occurs causing mechanical vibrations and potential damage

Engineering Contradiction:

Improvecompressor stabilityVSAvoidacoustic resonance

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies the acoustic black hole principle to convert harmful acoustic resonance energy into beneficial damping effects. The ABH structure absorbs resonant acoustic waves and converts them into structural vibrations that are dissipated as heat through viscous damping in the boundary layer, thereby eliminating the harmful resonance while maintaining the valve's flow control function

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The acoustic black hole assembly acts as an intermediary element between the acoustic field and the structural components. It mediates the interaction by absorbing acoustic energy and converting it to thermal energy through viscous dissipation, preventing the direct transmission of resonant vibrations to the compressor hardware

Inventive Principle:

Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If the variable bleed valve cavity is open, then acoustic resonance is reduced, but bleed flow control is compromised

Engineering Contradiction:

Improveacoustic resonanceVSAvoidbleed flow control

Core Design Contradiction:

Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The patent segments the valve assembly into distinct functional components: the variable bleed valve door for flow control, the acoustic black hole assembly for acoustic damping, and the compressor casing for structural support. This segmentation allows the valve to operate in closed position for flow control while the ABH assembly independently manages acoustic resonance, resolving the contradiction between flow control and acoustic stability

Inventive Principle:

Principle #1Segmentation

3Object-affected harmful factors

If the acoustic black hole assembly is added to the variable bleed valve, then acoustic resonance is dampened, but device complexity increases

Engineering Contradiction:

Improveacoustic resonanceVSAvoidvalve assembly structure

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The acoustic black hole assembly is nested within the existing variable bleed valve cavity structure. The ABH structure utilizes the same spatial envelope as the valve cavity, with the porous absorber material fitted within the cavity's internal volume. This nesting approach eliminates the need for separate external damping structures, thereby limiting the increase in overall device complexity while achieving effective acoustic resonance damping

Inventive Principle:

Principle #7Nested doll (Nesting)

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 acoustic black hole assembly effectively dampens acoustic resonance, minimizing mechanical vibrations and preventing damage to compressor components, thereby enhancing turbine engine stability and performance.

Implementation Method 1

The ABH structure absorbs resonant acoustic waves and converts them into structural vibrations that are dissipated as heat through viscous damping in the boundary layer

Methodology Applied

Scientific EffectViscous damping: Viscous Damping

Implementation Method 2

the acoustic black hole assembly effectively dampens acoustic resonance, minimizing mechanical vibrations

Methodology Applied

Scientific EffectAcoustic absorption: Acoustic Absorption

Data Source

PatentUS20250297576A1Variable bleed valve assemblies

Publication Date: 2025.09.25 GENERAL ELECTRIC CO

AI summary

Example variable bleed valve assemblies for a gas turbine engine are disclosed herein. An example variable bleed valve assembly includes a port extending radially outward from a main flow path of the gas turbine engine, a door positioned at an exit of the port, and an acoustic black hole (ABH) assembly coupled to the door. The ABH assembly includes a body and a plurality of plates coupled to an interior surface of the body. The body defines a cavity having a depth. Each of the plurality of plates has a surface area, and the plurality of plates are arranged such that the surface areas of the plurality of plates vary along the depth in a radially outward direction of the gas turbine engine.