| Budget Amount *help |
¥5,200,000 (Direct Cost: ¥4,000,000、Indirect Cost: ¥1,200,000)
Fiscal Year 2014: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2013: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
Fiscal Year 2012: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
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| Outline of Final Research Achievements |
In this study, the sound-absorption coefficients of the sound-absorbing structure using bundle of narrow clearances between a number of thin plates were measured for various formations and size. We discussed the experimental results and conducted a theoretical analysis on several different sound-absorbing structures that take into account the viscosity of the boundary layer at the clearances.
We developed a theoretical estimation method with respect to various cross sectional narrow hole bundle structures by using just their dimensions, and verified its effectiveness by comparing the results with those of experiments.
We placed these biomass resources at an incline with respect to the sound wave incident direction and obtained the following results. Arranging bundles of rice straw elements at an incline allows us to reduce the apparent thickness of sound-absorbing materials without impacting sound-absorption characteristics in the low-frequency range.
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