2015 Fiscal Year Final Research Report
Mechanism Clarification of a Fire Tornado Occurring in Great Earthquake Disaster from a Viewpoint of Vortex Dynamics
| Project/Area Number |
25560177
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| Research Category |
Grant-in-Aid for Challenging Exploratory Research
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| Allocation Type | Multi-year Fund |
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| Research Field |
Natural disaster / Disaster prevention science
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| Research Institution | Yamagata University |
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Principal Investigator |
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| Project Period (FY) |
2013-04-01 – 2016-03-31
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| Keywords | 火災旋風 / 渦・旋回流 / 重力・浮力 / 燃焼 / ラセン状の渦線 / 渦力学 / 数値シミュレーション / 防災・安全 |
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| Outline of Final Research Achievements |
In this study, it was attempted to clarify the structure and mechanism of a fire tornado from a viewpoint of vortex dynamics. The method of computational fluid dynamics (CFD) was used. As a result, the double structure consisting of inner helical vortex line and outer helical vortex line was found in the fire tornado, and the high-speed upward flow of combustion gas was also found in a gap region between the inner and outer helical vortex lines. This double structure of helical vortex lines and its induction flow velocity enabled the high-speed transport of combustion gas from the ground to the sky, keeping the combustion gas in the tornado-like slender cylindrical region. Therefore, the structure and mechanism found in this study seemed to be essentially important for the formation and sustainment of the fire tornado.
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| Free Research Field |
流体力学、燃焼学
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