Abstract
A class of metasurfaces for underwater sound absorption, based on a design principle that maximizes thermoviscous loss, is presented. When a sound meets a solid surface, it leaves a footprint in the form of thermoviscous boundary layers in which energy loss takes place. Considered to be a nuisance, this acoustic to vorticity/entropy mode conversion and the subsequent loss are often ignored in the existing designs of acoustic metamaterials and metasurfaces. The metasurface created is made of a series of topographic meta-atoms, i.e., intaglios and reliefs engraved directly on the solid object to be concealed. The metasurface is acoustically sticky in that it rather facilitates the conversion of the incident sound to vorticity and entropy modes, hence the thermoviscous loss, leading to the desired anechoic property. A prototype metasurface machined on a brass object is tested for its anechoicity, and shows a multitude of absorption peaks as large as unity in the 2-5 MHz range. Computations also indicate that a topographic metasurface is robust to hydrostatic pressure variation, a quality much sought-after in underwater applications.
| Original language | English |
|---|---|
| Pages (from-to) | 1537-1547 |
| Number of pages | 11 |
| Journal | Journal of the Acoustical Society of America |
| Volume | 143 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - 2018 Mar 1 |
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All Science Journal Classification (ASJC) codes
- Arts and Humanities (miscellaneous)
- Acoustics and Ultrasonics
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Acoustically sticky topographic metasurfaces for underwater sound absorption. / Lee, Hunki; Jung, Myungki; Kim, Minsoo; Shin, Ryung; Kang, Shinill; Ohm, Won Suk; Kim, Yong Tae.
In: Journal of the Acoustical Society of America, Vol. 143, No. 3, 01.03.2018, p. 1537-1547.Research output: Contribution to journal › Article
TY - JOUR
T1 - Acoustically sticky topographic metasurfaces for underwater sound absorption
AU - Lee, Hunki
AU - Jung, Myungki
AU - Kim, Minsoo
AU - Shin, Ryung
AU - Kang, Shinill
AU - Ohm, Won Suk
AU - Kim, Yong Tae
PY - 2018/3/1
Y1 - 2018/3/1
N2 - A class of metasurfaces for underwater sound absorption, based on a design principle that maximizes thermoviscous loss, is presented. When a sound meets a solid surface, it leaves a footprint in the form of thermoviscous boundary layers in which energy loss takes place. Considered to be a nuisance, this acoustic to vorticity/entropy mode conversion and the subsequent loss are often ignored in the existing designs of acoustic metamaterials and metasurfaces. The metasurface created is made of a series of topographic meta-atoms, i.e., intaglios and reliefs engraved directly on the solid object to be concealed. The metasurface is acoustically sticky in that it rather facilitates the conversion of the incident sound to vorticity and entropy modes, hence the thermoviscous loss, leading to the desired anechoic property. A prototype metasurface machined on a brass object is tested for its anechoicity, and shows a multitude of absorption peaks as large as unity in the 2-5 MHz range. Computations also indicate that a topographic metasurface is robust to hydrostatic pressure variation, a quality much sought-after in underwater applications.
AB - A class of metasurfaces for underwater sound absorption, based on a design principle that maximizes thermoviscous loss, is presented. When a sound meets a solid surface, it leaves a footprint in the form of thermoviscous boundary layers in which energy loss takes place. Considered to be a nuisance, this acoustic to vorticity/entropy mode conversion and the subsequent loss are often ignored in the existing designs of acoustic metamaterials and metasurfaces. The metasurface created is made of a series of topographic meta-atoms, i.e., intaglios and reliefs engraved directly on the solid object to be concealed. The metasurface is acoustically sticky in that it rather facilitates the conversion of the incident sound to vorticity and entropy modes, hence the thermoviscous loss, leading to the desired anechoic property. A prototype metasurface machined on a brass object is tested for its anechoicity, and shows a multitude of absorption peaks as large as unity in the 2-5 MHz range. Computations also indicate that a topographic metasurface is robust to hydrostatic pressure variation, a quality much sought-after in underwater applications.
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UR - http://www.scopus.com/inward/citedby.url?scp=85044296287&partnerID=8YFLogxK
U2 - 10.1121/1.5027247
DO - 10.1121/1.5027247
M3 - Article
C2 - 29604707
AN - SCOPUS:85044296287
VL - 143
SP - 1537
EP - 1547
JO - Journal of the Acoustical Society of America
JF - Journal of the Acoustical Society of America
SN - 0001-4966
IS - 3
ER -