1986 Fiscal Year Final Research Report Summary
Effects of particles on isotropic turbulence
| Project/Area Number |
60460102
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Fluid engineering
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| Research Institution | Osaka University |
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Principal Investigator |
YUTAKA Tsuji Faculty of Engineering, Osaka University, 工学部, 助教授 (10029233)
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| Co-Investigator(Kenkyū-buntansha) |
TANAKA Toshitsugu Faculty of Engineering, Osaka University, 工学部, 助手 (90171777)
YOSHIOKA Muneyuki Faculty of Engineering, Osaka University, 工学部, 助手 (10029267)
MORIKAWA Yoshinobu Faculty of Engineering, Osaka University, 工学部, 教授 (60029741)
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| Project Period (FY) |
1985 – 1986
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| Keywords | Multiphase Flow / Turbulence / スペクトル |
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| Research Abstract |
Mutual interaction between particle motion and fluid turbulence was investigated, which is regarded as the most fundamental subject in the field of multiphase flow. For that purpose, a vertical water tunnel in which water flows upwards was built and isotropic turbulence was generated by a grid. Comparatively large particles were used, the size of which was larger than the Kolmogoroff scale but smaller than the Taylor micro-scale. The fluid velocity was measured mainly by a hot wire velocimeter, because continuous values were required for the subsquent spectral analysis. Particle velocity and concentration were measured by a video recorder in combination with a frame memory and image processor. As the secondary step of the present work, the same problem was investigated in a turbulent boundary layer.
Results are summarized as follows.
(1) Uniformity in velocity and turbulence is difficult to obtain under the condition that particles are supplied to the flow.
(2) Large particles increase fluid turbulence and decrease dissipation rate of it.
(3) Large particles increase spectrsl components of higher wave numbers.
(4) A fluctuating velocity with low frequency which does not exist in a single phase flow was observed in the turbulent boundary layer including particles.
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Research Products
(6 results)
