1990 Fiscal Year Final Research Report Summary
Suppression Method of Flexible Structure Aerodynamic Vibration by Active Control of Accelerating Fluid in Separating Shear Flow.
| Project/Area Number |
01460171
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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 |
土木構造
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| Research Institution | Kyushu Institute of Technology |
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Principal Investigator |
KUBO Yoshinobu Kyushu Institute of Technology, Civil Engineering, Associate Professor., 工学部, 助教授 (70093961)
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| Co-Investigator(Kenkyū-buntansha) |
KATO Kusuo KYUSHU INSTITUTE OF TECHNOLOGY, CIVIL ENGINEERING, RESEARCH ASSISTANT., 工学部, 助手 (60039138)
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| Project Period (FY) |
1989 – 1990
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| Keywords | boundary layer control / aerodynamic response / suppression of aerodynamic vibration / surface pressure distribution / vortex-excited oscillation / galloping / flow visualization / super-long suspension bridge |
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| Research Abstract |
The present research has been conducted to find the method how to apply the boundary layer control method on the suppression of aerodynamic responses of bluff bodies. The useful informations for suppression of aerodynamic responses of bluff body were obtained from the fundamental experiments of measuring surface pressure and aerodynamic responses of square prism with two rotating cylinders set on upstream corners.
(1) The mean and fluctuating pressures can be controlled by controlling the rotary surface velocity of the rotating cylinder.
(2) The higher rotary surface velocity leads the bluff body to be a more stream-lined body. In other words, the bluff body can be improved to the elongated body by accelerating the boundary layer by the rotating cylinder.
(3) The most effective combination of rotary surface velocities of two rotating cylinders in the present research is the case that one is at rest and another is rotating with the velocity higher than 1.4 times of approaching flow velocity.
(4) The case that the both rotating cylinders have the same rotary surface velocity has the tendency that the higher rotary surface velocity leads the aerodynamic responses to the higher on-set wind velocity of the galloping responses of the square cylinder.
(5) The aerodynamic responses can be completely suppressed by the one rotary cylinder owing to disappearance of alternative surface pressure fluctuations between upper and lower side surface pressure.
The extensive research will be conducted how to apply this method to the practical structures of super-long suspension bridges and super-high buildings which are proposed by Japanese government and some Japanese companies.
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