Volumetric diffusers: pseudorandom cylinder arrays on a periodic lattice
Hughes, RJ, Angus, JAS, Cox, TJ, Umnova, O, Gehring, GA, Pogson, M and Whittaker, DM 2010, 'Volumetric diffusers: pseudorandom cylinder arrays on a periodic lattice' , Journal of the acoustical society of america , 128 (5) , pp. 2847-2856.
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Most conventional diffusers take the form of a surface based treatment, and as a result can only operate in hemispherical space. Placing a diffuser in the volume of a room might provide greater efficiency by allowing scattering into the whole space. A periodic cylinder array (or sonic crystal) produces periodicity lobes and uneven scattering. Introducing defects into an array, by removing or varying the size of some of the cylinders, can enhance their diffusing abilities. This paper applies number theoretic concepts to create cylinder arrays that have more even scattering. Predictions using a Boundary Element Method are compared to measurements to verify the model, and suitable metrics are adopted to evaluate performance. Arrangements with good aperiodic autocorrelation properties tend to produce the best results. At low frequency power is controlled by object size and at high frequency diffusion is dominated by lattice spacing and structural similarity. Consequently the operational bandwidth is rather small. By using sparse arrays and varying cylinder sizes, a wider bandwidth can be achieved.
|Themes:||Subjects / Themes > Q Science > QC Physics > QC221-246 Acoustics - Sound|
Subjects outside of the University Themes
|Schools:||Colleges and Schools > College of Science & Technology|
Colleges and Schools > College of Science & Technology > School of Computing, Science and Engineering
Colleges and Schools > College of Science & Technology > School of Computing, Science and Engineering > Acoustics Research Centre
|Journal or Publication Title:||Journal of the acoustical society of america|
|Publisher:||Acoustical Society of America|
|Depositing User:||TJ Cox|
|Date Deposited:||13 Apr 2011 15:54|
|Last Modified:||27 Sep 2011 12:11|
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