Elucidation of Transient Structure of Flow Field of Moving Tornado and Establishment of Identification Method of Tornado Characteristic Value by Images

2017 Fiscal Year Final Research Report

• Project/Area Number: 15H04034
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Structural engineering/Earthquake engineering/Maintenance management engineering
• Research Institution: Kochi University (2017); The University of Tokushima (2015-2016)
• Principal Investigator: Noda Minoru 高知大学, 教育研究部自然科学系理学部門, 教授 (30283972)
• Co-Investigator(Kenkyū-buntansha): 長尾 文明 徳島大学, 大学院社会産業理工学研究部(理工学域), 教授 (40172506)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 竜巻シミュレータ / 竜巻状流れ / デブリ雲 / 漏斗雲 / 強風災害 / 竜巻災害 / PIV

Outline of Final Research Achievements

In order to investigate the properties of the flow field of a tornado-like flow, a tornado simulator with multi-fan, multi-vane and moving belt was developed to reproduce the moving state. As results of measurement by 3D-PIV, it was confirmed that three types of tornado-like flow of one cell, two cells and multi vortexes were stably generated, and the moving state can be reproduced. In addition, as a result of the flight analysis of debris in tornado-like flow generated by LES, it was found that the frequencies of occurrence of the arrival radius, the maximum tangential velocity, and so on, are similar to the normal distribution. This result says that the collision speed of debris in tornado-like flow can be set based on the exceedance probability. Furthermore, it was clarified that there is a certain relationship between the shape and scale of funnel cloud and the strength and scale of tornado.

Free Research Field

構造工学・地震工学・維持管理工学