Combustor Wall Core Resonators for Acoustic Damping and Cooling
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Solution Overview
Problem
Ramjet and scramjet engines with rotating detonation combustors produce high-amplitude acoustic pressure signals that adversely affect operability and engine electronics, necessitating a solution to mitigate these effects.
Innovation Solution
An engine assembly with a combustor wall featuring a core structure comprising resonator elements and damper elements, which includes sound attenuation and cooling passages to attenuate sound waves and dissipate heat, thereby reducing acoustic pressure and vibrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If resonator elements are added to the combustor wall core, then sound attenuation improves, but device complexity increases
Solution Approach 1:
The combustor wall core utilizes a porous metallic foam structure that inherently provides sound attenuation properties. The porous nature of the foam creates numerous small cavities and tortuous flow paths that dissipate acoustic energy through viscous effects and thermal conduction, effectively reducing high-amplitude acoustic pressure signals without requiring additional complex components.
Solution Approach 2:
The combustor wall structure is designed to perform multiple functions simultaneously: the core provides both structural support and sound attenuation, while integrated cooling passages enable thermal management. This multi-functionality reduces overall device complexity by combining what would otherwise require separate components into a single integrated structure.
2Temperature
If cooling passages are integrated into the core, then heat dissipation improves, but manufacturing complexity increases
Solution Approach 1:
The invention utilizes additive manufacturing technology to create complex three-dimensional cooling passages within the combustor wall core. This manufacturing approach enables the formation of intricate internal geometries that would be difficult or impossible to achieve with traditional subtractive manufacturing methods, thereby improving heat dissipation while managing manufacturing complexity through advanced fabrication techniques.
Solution Approach 2:
The cooling passages are nested within the porous core structure, with the passages forming an internal network inside the combustor wall. This nested arrangement allows efficient heat removal from the combustion chamber while maintaining the external dimensions and structural integrity of the combustor wall, optimizing thermal management without excessive manufacturing complexity.
3Object-affected harmful factors
If the sound attenuation passage extends into the resonator element, then acoustic attenuation improves, but device complexity increases
Solution Approach 1:
The sound attenuation passage is merged with the resonator element structure, where the passage walls form an integral part of the resonator's geometry. This integration allows the resonator to function both as a structural component and as an acoustic attenuation element, reducing the need for separate sound treatment components and simplifying the overall device architecture.
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 assembly effectively attenuates sound waves and dissipates heat, improving engine operability and reducing vibrations, thus enhancing the performance and reliability of ramjet and scramjet engines.
Implementation Method 1
The core includes a plurality of resonator elements between the first skin and the second skin. The resonator elements include a first resonator element. The first resonator element includes a first base and a plurality of first protrusions projecting out from the first base. Each of the first protrusions includes a first bore fluidly coupled with a first cavity within the first base.
Implementation Method 2
The sound attenuation passage extends within the core and is fluidly coupled with the combustion volume through an attenuation passage aperture in the first skin. The sound attenuation passage is fluidly decoupled from the plenum by the second skin.
Implementation Method 3
The combustor wall also includes a cooling passage extending within the core. The cooling passage is fluidly coupled with the combustion volume through a first skin cooling passage aperture in the first skin. The cooling passage is fluidly coupled with the plenum by a second skin cooling passage aperture in the second skin.
Data Source
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AI summary
An engine assembly includes a combustor wall with a first skin, a second skin, a core and a sound attenuation passage. The first skin forms a peripheral boundary of a combustion volume on a first side of the combustor wall. The second skin forms a peripheral boundary of a plenum on a second side of the combustor wall. The core includes a plurality of resonator elements between the first skin and the second skin. A first resonator element includes a first base and a plurality of first protrusions projecting out from the first base. Each first protrusion includes a first bore fluidly coupled with a first cavity within the first base. The sound attenuation passage extends within the core and is fluidly coupled with the combustion volume through an attenuation passage aperture in the first skin. The sound attenuation passage is fluidly decoupled from the plenum by the second skin.