| 摘要 |
PROBLEM TO BE SOLVED: To save costs for designing and developing acoustic components such as new sound absorbers by making it possible to estimate sound characteristics rather easily and correctly for fiber assemblies, such as felt and glass wool. SOLUTION: The characteristic impedance Zc of fiber aggregates, such as felt and glass wool is calculated from formula (Fig.31) by using the effective densityρ<SB>eff</SB>, the volume elasticity K<SB>f</SB>, and the constant C specific to the diameter of the fiber. The propagation constantΓis calculated from formula (Fig.32) by using this densityρ<SB>eff</SB>, and the volume elasticity K<SB>f</SB>. The acoustic impedance Z<SB>0</SB>is calculated from formula (Fig.33) by using the characteristic impedance Zc and the propagation constantΓ. The vertical incident sound absorption coefficientα<SB>0</SB>is calculated from formula (Fig.34) by using the acoustic impedance Z<SB>0</SB>. COPYRIGHT: (C)2007,JPO&INPIT
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