1996 Fiscal Year Final Research Report Summary
Study on shaking phenomenon of branches by strong wind and windbreak structure.
| Project/Area Number |
07660351
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
生物環境
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| Research Institution | Tokai University |
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Principal Investigator |
TANAKA Hiromichi Tokai University・Marine Science and Technology・Associate Professor, 海洋学部, 助教授 (90134014)
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| Co-Investigator(Kenkyū-buntansha) |
FUJIWARA Hirokazu Hachinohe National College of Technology・Civil Engineering・Lecture, 建設環境工学科, 講師 (70199389)
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| Project Period (FY) |
1995 – 1996
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| Keywords | Typhoon disaster / Fruit drop / Shaking blanche / Windbreak structure / ヤング率 |
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| Research Abstract |
Many apples dropped by a Typhoon 9119 in Aomori Prefecture, and fruiters sustained great damege.
In this studies, first, we studied on the turbulent characteristic of wind near the ground, we elucidated a shaking phenomenon of branches by the strong wind, and considered the windbreak structure.
As the result of them we obtained the following the concluding remarks.
(1) Horizontal wind velocity is the structure to combine the low frequency and the hight frequency.
(2) The turbulent intensity of horizontal and vertical wind velocity increases as horizontal wind velocity increases.
(3) The Young's modulus of the branches of apple was E=2.4-4.0gf/cm^2 in the like-values for another fruit trees (pear, persimmon and peach).
(4) The fluctuations of apples by wind are large in the direction of back and forth are larger than the direction of rise and fall, right and left.
(5) The fluctuations of apples by wind influenced on the magnitude of fluctuating velocity more than the magnitude of velocity.
(6) The shaking branches and apples were related to the gustiness.
(7) The fluctuations of apples behind the windbreak net were not influenced by the strength and the fluctuations of the wind speed.
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