Absorption of low-frequency sound by a resonant metasurface Seminar
- Time:
- 16:00 - 17:00
- Date:
- 3 May 2016
- Venue:
- Building 13 room 3017
Event details
ISVR Engineering Research seminar
Logan Schwan 1, Olga Umnova 2 and Claude Boutin 3
1 LAUM, Universite du Maine, France
2 Acoustics Research Centre, University of Salford, UK
3 ENTPE, Universite de Lyon, France
In collaboration with S.Taherzadeh and K. Attenborough (Open University, UK)
The work is devoted to theoretical and experimental investigation of a resonant acoustic metasurface for total sound absorption at low frequencies. An equivalent admittance model is developed using the two-scale asymptotic homogenization method. Based on the model, the metasurface is built and tested in both impedance tube and anechoic chamber. The metasurface is composed of a regular array of spherical Helmholtz resonators with internal neck and is more than 25 times thinner than the wavelength of the absorbed sound. It is shown that: (a) the total absorption of a plane wave normally or obliquely incident on the surface can be achieved by tuning the design of the resonators and their arrangement on the backing; and (b) the design is robust enough to achieve high absorption levels even when the incident wave is not plane and the metasurface has dimensions of the order of the wavelength. Other applications, such as enclosure mode control and sound absorption by curved arrays, are also discussed. (The work is supported by EPSRC, project EP/K037234/1)
Speaker information
Olga Umnova , University of Salford. Olga Umnova is a Reader in Acoustics at the Acoustics Research Centre, University of Salford. She has graduated from Moscow Institute of Physics and Technology, Moscow with MSc in Physics. The subject of her PhD got her PhD was nonlinear ultrasound. Her research interests include acoustics of heterogeneous media, nonlinear acoustics and, more recently, sonic crystals, acoustic metamaterials and metasurfaces.