Vortex Acoustic Black Hole Structure for Low-Frequency Vibration Damping
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Solution Overview
Problem
Existing vibration damping technologies, such as tuned mass dampers and vibration damping materials, face limitations in frequency band width, weight increase, and space requirements, while acoustic black holes require large spaces to absorb low-frequency elastic waves effectively.
Innovation Solution
A two-dimensional acoustic black hole (ABH) apparatus composed of vortex-shaped structures that absorb and dissipate elastic waves efficiently, even with a small size, by utilizing geometric characteristics to maximize effective propagation length and reduce installation space.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional acoustic black hole is used to absorb low-frequency elastic waves, then vibration damping performance is improved, but the installation space required increases
Solution Approach 1:
The patent transitions from a one-dimensional acoustic black hole (single vortex structure) to a two-dimensional acoustic black hole (multiple vortex structures arranged in rotational pattern). This dimensional expansion allows the system to achieve equivalent vibration damping performance with reduced installation area by distributing the elastic wave absorption function across multiple vortex parts arranged circumferentially
Solution Approach 2:
The patent divides the acoustic black hole structure into multiple discrete vortex parts (first vortex part, second vortex part, etc.) arranged in a rotational pattern. Each vortex part handles a portion of the elastic wave absorption, allowing the system to achieve comprehensive low-frequency vibration damping while occupying less total space than a single large-scale acoustic black hole
2Reliability
If vibration damping material is attached thickly to wide surface, then vibration energy dissipation is improved, but weight of structure increases
Solution Approach 1:
The patent replaces the conventional approach of attaching thick vibration damping materials (mechanical energy dissipation through material deformation) with an acoustic black hole structure that utilizes elastic wave propagation and geometric acoustics principles. The vortex-shaped structures guide and concentrate elastic waves, enabling effective vibration energy dissipation with minimal material thickness and reduced structural weight
3Reliability
If tuned mass damper is used to reduce vibration at targeted frequency, then vibration reduction is improved, but unwanted vibration is amplified at nearby frequencies
Solution Approach 1:
The patent creates a multi-functional vibration control system where the two-dimensional acoustic black hole structure simultaneously handles multiple frequency ranges through its array of vortex parts. The rotational arrangement of different vortex structures enables the system to absorb elastic waves across a broad frequency spectrum, providing universal vibration damping performance without the frequency-selective limitations and unwanted amplification effects of tuned mass dampers
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 apparatus achieves superior vibration damping performance across a wide frequency range, including low frequencies, with a compact design that minimizes space requirements and enhances vibration reduction.
Implementation Method 1
A representative technology for vibration damping includes... an acoustic black k hole, a wave-based concept that has been actively studied in academia recently. The acoustic black hole may significantly dampen vibrations by causing almost no reflection of elastic waves above a specific frequency when the elastic waves are incident
Implementation Method 2
a method of attaching a vibration damping material that is attached to a front of a structure and dissipates vibration energy into heat energy
Implementation Method 3
A tuned mass damper, which is a first example of the background technology, absorbs vibration energy based on resonance
Data Source
AI summary
The technology of increasing space efficiency and vibration damping performance by designing a structure capable of sufficiently reducing low-frequency vibrations while occupying a relatively small space is proposed. In particular, a cut-on frequency of an acoustic black hole is reduced so that low-frequency vibrations may be absorbed by increasing a length of an effective wave propagation path using geometric characteristics of a vortex shape even when it occupies the same area.