Wind Speed of Tornado to Make a Road Damage
Minoru Noda and Fumiaki Nagao
*The University of Tokushima, 2-1 Minami-Josanjima, Tokushima 770-8506, Japan
Three tornadoes almost simultaneously hit the northern Kanto region north of Tokyo, Japan, on May 6, 2012. One peeled away and scattered asphalt 4 m wide, 30mlong and 50mmthick from roads in Tochigi prefecture. According to the Japan Meteorological Agency, the F scale of this tornado was between F1 and F2. A few F1-F2 tornadoes occur in Japan each year, but the scale of road damage following an F1-F2 tornado has not been previously observed. To determine the wind speed behind this road damage, a new approach was adopted focusing on the speed of flying debris and the pressure drop. The resulting determined a wind speed of approximately 100 m/s.
-  Japanese Meteorological Agency, 2012,
http://www.jma.go.jp/ [accessed October 16, 2013]
-  T. T. Fujita, “Proposed Characterization of Tornadoes and Hurricanes by Area and Intensity,” Satellite and Mesometeorology Research Project Paper, No.91, 1971.
-  J. MacDonald, K. Mehta, D. Burgess, J. Schaefer, M. Riley, and B. Smith, “A Recommendation for an Enhanced Fujita Scale (EFScale),” Wind Science and Engineering Center, Texas Tech University, 2004.
-  Japan Road Association, “Installation standards of Guard fence and Commentary,” Maruzen Co, Ltd, 2008 (in Japanese).
-  M. Noda and F. Nagao, “Simulation of 6DOF motion of 3D flying debris,” Proceedings of 5th International Symposium on Computational Wind Engineering, 2010.
-  M. Noda and F. Nagao, “Behavior of Plate-like flying debris,” Proceedings of 13th International Conference on Wind Engineering, 2011.
-  M. Tachikawa, “Trajectories of flat plates in uniform flow with application to wind-generated missiles,” Journal of Wind Engineering and Industrial Aerodynamics, Vol.14, pp. 443-453, 1983.
-  J. D. Holmes, C. J. Baker, and Y. Tamura, “Tachikawa number: A proposal,” Journal of Wind Engineering and Industrial Aerodynamics, Vol.94, pp. 41-47, 2006.
-  G. R. Sabareesh, M.Matsui, and Y. Tamura, “Characteristics of surface pressure on a building under a tornado-like flow at different swirl ratios,” Journal of Wind and Engineering, Vol.8, No.2, pp. 30-40, 2011.
-  OpenCFD Ltd (ESI Group), “OpenFOAM,” 2013, http://www.openfoam.com [accessed October 16, 2013]
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