| Presentation | 2005/5/6 Numerical analysis of sonic/phononic crystals and acoustic wave-guides with the finite-difference time-domain method Toyokatsu MIYASHITA, |
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| Abstract(in Japanese) | (See Japanese page) |
| Abstract(in English) | We are engaged in the theoretical and experimental investigations of sonic/phononic crystals which are composed of a periodic array of a finite number of acoustic scatterers in a uniform host material. Our main aim is to apply them to measurement of waves, to controling of wave progagation, and more generally to acoustic circuits. First we present an effective and practical way to fulfil the numerical stability condition, namely Courant condition, in the application of FDTD method to the numerical investigations of cystals. Second we compare the numerically obtained band-gap structures of crystals as sonic crystals where only longitudinal waves are relevant and those obtained as phononic crystals where shear waves play important roles too, and we get the following conclusions. Sonic crystals composed of methacrylic resin cylinders in air and also crystals of aluminum cylinders in air have only slightly higher band-gaps by 0.01～0.02 in the normalized frequency when they are calculated as elastic materials. On the other hand, phononic crystals of a periodic array of steel cylinders in water proved to have much higher band-gaps by 0.06～0.08 in the normalized frequency than when they are treated as sonic crystals. Third we show the existence of so-called defect modes, which is a narrow resonating and filtered pass-band appearing in the full band-gap of sonic/phononic crystals. |
| Keyword(in Japanese) | (See Japanese page) |
| Keyword(in English) | sonic crystal / phononic crystal / full band-gap / defect mode / FDTD method |
| Paper # | US2005-14 |
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| Conference Information | |
| Committee | US |
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| Conference Date | 2005/5/6(1days) |
| Place (in Japanese) | (See Japanese page) |
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| Topics (in Japanese) | (See Japanese page) |
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| Paper Information | |
| Registration To | Ultrasonics (US) |
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| Language | JPN |
| Title (in Japanese) | (See Japanese page) |
| Sub Title (in Japanese) | (See Japanese page) |
| Title (in English) | Numerical analysis of sonic/phononic crystals and acoustic wave-guides with the finite-difference time-domain method |
| Sub Title (in English) | |
| Keyword(1) | sonic crystal |
| Keyword(2) | phononic crystal |
| Keyword(3) | full band-gap |
| Keyword(4) | defect mode |
| Keyword(5) | FDTD method |
| 1st Author's Name | Toyokatsu MIYASHITA |
| 1st Author's Affiliation | Dept. Electronics & Informatics, Ryukoku University() |
| Date | 2005/5/6 |
| Paper # | US2005-14 |
| Volume (vol) | vol.105 |
| Number (no) | 44 |
| Page | pp.pp.- |
| #Pages | 6 |
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