| Project/Area Number |
12450231
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Architectural environment/equipment
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| Research Institution | The University of Tokyo |
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Principal Investigator |
HIRATE Kotaroh Grad. Sch. of Eng., Assoc. Prof., 大学院・工学系研究科, 助教授 (70165182)
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| Co-Investigator(Kenkyū-buntansha) |
OSHIMA Takaya Fac. of Eng. Univ. of NIIGATA, Research Assoc., 工学部, 助手 (40332647)
SAKUMA Tetsuya Grad. Sch. of Fren, Sci., Assoc. Prof., 大学院・新領域創成科学研究科, 助教授 (80282995)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥7,500,000 (Direct Cost: ¥7,500,000)
Fiscal Year 2001: ¥2,900,000 (Direct Cost: ¥2,900,000)
Fiscal Year 2000: ¥4,600,000 (Direct Cost: ¥4,600,000)
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| Keywords | Building Exterior Subsidiaries / Aeroacoustics / Numerical Analysis / CFD / Bluff Body / Computational Cost Reduction / LES / Sound Source Correlation / 強風 / 空力騒音 / Lighthill-Curle 理論 / 流入風向 / 放射音圧推定 / 相関係数 / Lighthill-Curle理論 / Smagorinskyモデル |
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| Research Abstract |
True-scale analysis : Sound generation by airflow over square-section balusters of buildings is numerically calculated by a hybrid technique of near-field incompressible flow analysis and far-field integral of Curle equation. Under the conditions of inflow wind velocity of 12m/s and the side length of the square-section balusters of 21mm (the Reynolds number 16,000), the result approximately matched an experimental result in peak frequency, which is higher in Strouhal number than the case of an isolated square cylinder in the same Reynolds number.
Computational cost reduction method : An estimation method of total sound pressure radiated from such body is introduced by conducting an analysis of its partial span, taking frequency-dependent spanwise correlation of the fluctuating aeroacoustic source into account. The presented method is validated through comparison of the sound pressure estimated by the method and that obtained by a full-span analysis.
Extension to the method above : To reduce computational resources required for CFD computation further, the authors present a method to estimate the noise from a row of cylinders like balusters by computing its part. The idea is to extrapolate the sound pressure obtained by partial computation using correlation function of the phase angles of fluid forces at each frequency between the cylinders. A computation of a balustrade with eight balusters with the method applied is attempted, where correlation is hardly observed even at the Karman frequency.
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