Outbreak of Hazardous Local Gusts by Interactions of Gradient of Potential Temperature near the Ground with Surrounding Terrain Effect

近地面位温梯度与周围地形效应相互作用导致局部危险阵风爆发

• 批准号: 16360279
• 负责人: MAEDA Junji
• 金额: $ 9.73万
• 依托单位: KYUSHU UNIVERCITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-16360279/
• 关键词: wind disaster; CFD; gradient of potential temperature; local wind; wind tunnel test; aerologic observation; Froude number; 強風災害; 台風; 風速プロファイル; 山稜地形

Our study showed how the interaction of the gradient of potential temperature near the ground and the configuration of surrounding terrain affects the development of a stronger wind gust using some observation examples and numerical simulation and paying attention to the phenomenon in which the strong wind running over a ridge during a typhoon passage becomes stronger near the foot of a mountain.(1)A cooling box mounted in a floor of a wind tunnel could make a stronger temperature gradient of an approaching flow in a small wind tunnel by combining a device which heats an upper layer of an approaching air by a hot wire.(2)Some wind tunnel tests showed that a temperature gradient, i.e., stability of atmospheric air, affected strongly the growth of a strong wind region near the leeward foot of a two-dimensional mountain model.(3)In the case of the two-dimensional mountain model which has a V-shaped valley, some wind tunnel tests showed the generation of the strong wind region different fr … More om the two-dimensional mountain model.(4)A parametric study on the wind flow over the mountain ridge line with a valley by several commercially available software shows that the locations of the simulated strong wind regions were in good agreement with the wind-tunnel-test result.(5)Although Ogi City in Saga Prefecture was no less than 300km away from the course of Typhoon No.23 in 2004, the big wind damage concentrated in the area. Some analyses by our numerical simulation indicated that a shallow valley in a 1000-meter high mountain which is located in a windward of Ogi City had affected strongly the acceleration of the strong winds in the area. Moreover, the simulation results became more similar to the observed wind speed at the site by taking in the data of actual aerologic observation data for the initial condition (wind-speed inflow conditions) of the calculation.(6)I think, however, the present numerical-simulation technique is difficult to realize precise reproduction of the instantaneous wind speed containing high-frequency components of gust. For forecasting of actual peak gusts, the further creative ingenuity of wind flow simulation is required.(7)Similarly as a result of parametric study of outbreak of a strong local wind seen at the western Fukuoka City area in March, 1998, it turned out that the development of the strong gust in this region can be better reproduced by operating the gradient of potential temperature with Froude number of about 1.6 in addition to the surrounding terrain effect. Less

我们的研究通过一些观测实例和数值模拟，并关注台风过境期间越过山脊的强风在靠近山脚处变得更强的现象，揭示了近地面位温梯度和周围地形结构的相互作用如何影响更强的阵风发展。（1）安装在风洞地板上的冷却箱可以使接近气流的温度梯度更强 (2)一些风洞试验表明，温度梯度，即大气的稳定性，强烈影响二维山体模型背风脚附近强风区域的生长。(3)对于具有V形山谷的二维山体模型，一些风洞试验表明强风的产生 (4)通过多种市售软件对带山谷的山脊线风流进行参数化研究表明，模拟的强风区位置与风洞试验结果吻合较好。(5)虽然佐贺县小木市距离2004年第23号台风路径不少于300公里，但大风灾主要集中在 区域。我们的数值模拟分析表明，位于小木市迎风面的一座千米高山的浅谷对该地区强风的加速影响很大。而且，通过引入实际高空观测数据作为计算的初始条件（风速流入条件），模拟结果与现场观测风速更加接近。（6）但我认为，现有的数值模拟技术很难实现包含阵风高频分量的瞬时风速的精确再现。对于实际阵风峰值的预测，还需要风流模拟的进一步创新。(7)同样，对1998年3月福冈市西部地区发生局地强风的参数化研究结果表明，除了周围地形效应外，通过操作弗劳德数约为1.6的位温梯度，可以更好地再现该地区强阵风的发展过程。较少的

项目成果

台風0423号通過時における佐賀県小城市周辺風況のCFD解析

0423号台风过境时佐贺县小木市周边风况的CFD分析

• 发表时间: 2006
• 期刊: 都市・建築学研究(九州大学院人間環境学研究員紀要) 第10号
• 作者: 友清衣利子;喜多村美保;内田孝紀;前田潤滋
• 通讯作者: 前田潤滋

Tornado Disaster in Saga Prefecture, Japan on June 27, 2004

2004年6月27日日本佐贺县龙卷风灾难

• 发表时间: 2005
• 期刊: Proceedings of The Sixth Asia-Pacific Conference on Wind Engineering (APCWE-VI) CD
• 作者: Junji Maeda;Eriko Tomokiyo
• 通讯作者: Eriko Tomokiyo

一様流中の2次元崖状地形まわりの気流性状に関する数値的研究

二维悬崖地形均匀流周围气流特性数值研究

• 发表时间: 2005
• 期刊: 応用力学論文集 Vol.7
• 作者: 内田孝紀;大屋裕二
• 通讯作者: 大屋裕二

台風中心からの距離に着目した台風通過時の九州における風速分布の検討

以距台风中心距离为中心的台风过境期间九州风速分布研究

• 发表时间: 2006
• 期刊: 第19回風工学シンポジウム論文集
• 作者: 前田久雄;前田潤滋;友清衣利子
• 通讯作者: 友清衣利子

Gust Properties of Typhoons striking the Kyushu Area in 2004-Comparison with Typhoons in the 1990s

2004年九州地区台风的阵风特性——与1990年代台风的比较

• 发表时间: 2005
• 期刊: Proceedings of The Sixth Asia-Pacific Conference on Wind Engineering (APCWE-VI) 6
• 作者: Hisao Maeda;Eriko Tomokiyo;Junji Maeda
• 通讯作者: Junji Maeda