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Time domain sound field analysis by finite element method-Comparison of iterative methods and analysis of small hall-○奥園健

OKUZONO Takeshi¿P2007. 5

大鶴徹

OTSURU Toru

岡本則子

OKAMOTO Noriko

末吉俊秀

SUEYOSHI Toshihide

Architectural Acoustics lab., Oita Univ., Japan, O2L

研究の背景2V;hE
g±>2FGL2HN
2!>-1jÇµ®>-1~'jÇ

0N1<DK¬>Fg±,N?K3­Ð" ^>c0¬>Á×_¼]o8l0N1<DK4ËIA0x'2!>-1jÇhÓ¤
2!>'Ç&¯'*),N?K3­ ªÆt*hÉ "ÖÓ* )$« qÕ¤$3◉ Y70²È>-&a¿P2007. 5/ 

Architectural Acoustics lab., Oita Univ., Japan, O2L

研究の背景WT <I>4b;hE"*!$5ÑÜ%F]c0)
ÎPÔÇFEMPÎPZÂÇFDM<)ÔÇBEM
・Their applications is generally limited to low frequencies and/or simple room shape.
・Finite- and boundary-element methods can be ..., and work well for small rooms witharbitrary geometry at low frequencies.
◉ A. Wareing et al., J. Acoust. Soc. Am. 118 (4), pp 2321-2331, 2005

WT <I>4bGd;> #◉ T. Otsuru et al., Proc. ICA 2004(Kyoto), I-479-I-482, 2004.

FEM

 12000 m3 DK+v1k Hz"lµ~­+]o◉ S. Sakamoto et al., International Symposium on Room Acoustics : Design and Science 2004.

FDTD

 6000 m3 DK+v1.4 kHz"lµ~Â+$,N?K3­+]o◉ ©Ò%, I>K:&bÚPAA-2005-12P2005.

FMBEM  3000 m3 DK+v500 Hz"lµ~­+]o¿P2007. 5

Architectural Acoustics lab., Oita Univ., Japan, O2L

研究の背景FEMGd;>' #
Large-scale Finite Element Sound Field Analysis : LsFE-SFA
 27 §3AI,N>Ô*· ¸¾'Ç¥Ó +3/JN.*· mN}UÞ*·◉ Otsuru T et al., J. Acoust. Soc. Jan(E), 21(2), 87-95 2000
◉ T. Otsuru et al., Proc. ICA 2004(Kyoto), I-479-I-482, 2004.
◉ Okamoto N et al., The 9th Western Pacific Acoustics Conference, 2006

4Ë'!¥Ó 7W<S>%L2V;-S>-r-r f%kAbTDFEM

K@S*9r4ËA0!¥Ó ◉ T. Otsuru et al., inter noise94,ËDgig◉ @P²È>-&a, 1996

+ $&*RGd;hE+¿P2007. 5

Architectural Acoustics lab., Oita Univ., Japan, O2L

本研究の目的-rf%kAbGd;hE3$Gduo .aM1&nNYk3$
Í§ "*!$)
4ËA0Vlµ~Ý"'-!#"% <Zc <0gQ,uoYk¿P2007. 5.aM1Architectural Acoustics lab., Oita Univ., Japan, O2LGduo.aM1bKrylov\^X]b

CG, GMRes, QMR, BiCGStab etc...

mP:'() _t"*B=p]Çw B~UÞ»5MÔ#5 [A]{x}={b} +9'"´1È]  UÞB-<K
 ±eHP 6D[COj eH F ¸¾]$£]¶)"´¥Ó)Í&(k)¸¾'Çk B~UÞ3C-<K=)`-rf%kAb\^ bOj◉ T. Okuzono et al., Inter noise2006, 2006.

¿P2007. 5

Architectural Acoustics lab., Oita Univ., Japan, O2L

必要記憶容量の概算式
Ykiq2i?!
Required memory, RM [GByte]100

 / d > 4.4iq*1

fmax =4 kHz75

fmax =2 kHzfmax =1 kHz  / d  f max  3[Byte]
RM  1600V cfmax =250 Hz

f max 'wPlµ~ [Hz]
 / dµ Ô§0;Ø

50
fmax =500 Hz
2516 GByte00¿P2007. 5

10,00020,00030,0003
Room's volume, V [m ]40,00038000 m3c  [m/s]
V gÑ

[m3]

＃27§3AI,NÔ＃mN}E<J-3＃=GE-OÇ＃¸¾'ÇIN8H3M×1'ÇArchitectural Acoustics lab., Oita Univ., Japan, O2L

解析例 1

小ホール内音場解析O <N>3<12µ, fc = 250, 500 Hz

FE解析の設定>Ô 27§3AI,NÔ8926001
fÏª~
300 ms'c0 c03:9A~ 13,230z

(-7.558, 0.0, 1.50)
SSyx

AM491~ 6(250 Hz),8(500 Hz)
OpenMP&)ÄÞÅÊ8¢|¡>,N@7N3ºznsÅ zn =  W¦ zn = 1.0¿P2007. 5

Architectural Acoustics lab., Oita Univ., Japan, O2L

rDK±µ¨¹"`V   ÃÊ0.04 s

SS

yx

[Pa]

小ホール内音場解析における反復解法の収束性
X]bUJeHP 6D[COj eH25F 

IterationnumberNmv
fc = 250 Hz
fc = 500 Hz

2015

fc [Hz] Average of iteration number
2505001013.814.7500¿P2007. 55000
10000
Time step15000¸¾(~Ã?

n~(£ªiq14 GByte"*-94 h (250 Hz)
101 h (500 Hz)

Architectural Acoustics lab., Oita Univ., Japan, O2L

解析例 2 大規模多目的ホール内音場解析

y¿P2007. 5

Ñ 37,184 m3
Ê 2,844 m2[~2,572 Architectural Acoustics lab., Oita Univ., Japan, O2L

FE解析の設定
>Ô 27§3AI,NÔ196090
fÏª~
1000 ms
'c0 c03:9A~ 20000

1

Amplitude
1.0

Apmlitude

0.8

0.5

0.6

00.4

-0.5-10.00¿P2007. 5

0.2

0.05

0.100.15
Time [s]

0.20

0200

400 600 800
Frequency [Hz]1,000

Architectural Acoustics lab., Oita Univ., Japan, O2L4ËÌ¤DK±µ¨¹"`sound source

1P1

Normalized sound pressure

0.5
0-0.5

yx

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0.0

FEM

0.2

0.4
0.6
Time [s]

Meas.

0.8

1.0

iq4.9 GByte "*-127 hArchitectural Acoustics lab., Oita Univ., Japan, O2L

まとめ-rf%kAbGd;hE3$

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今後の課題]¢G#u\ªJth%~'jÇº,S)]V¿P2007. 5

Architectural Acoustics lab., Oita Univ., Japan, O2L

今後の課題ÅÊ8¢Ó )À>,N@7N3;6B3
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Architectural Acoustics lab., Oita Univ., Japan, O2L