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

基本信息

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

项目摘要

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，揭示了近地面位温梯度与周围地形结构的相互作用如何影响更强阵风的发展，并关注强风掠过地面的现象。台风过境时的山脊在山脚附近变得更强。(1)安装在风洞地板上的冷却箱可以通过结合加热和冷却装置，使小型风洞中接近的气流具有更强的温度梯度。热空气接近的上层(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)在二维山地模型具有V形山谷，风洞试验表明，其强风区的产生与二维山地模型不同。(4)山地风流参数化研究山脊线与山谷由几个商业现有软件显示，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号台风的路径不小于300km ，大风害集中在该地区，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风速的影响很大。而且，计算的初始条件（风速流入条件）采用了实际高空观测数据，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，而对于实际阵风峰值的预测，风流模拟的进一步创新之处在于。 (7) 同样，对 1998 年 3 月福冈市西部地区发生的局地强风进行参数研究的结果表明，通过操作可以更好地再现该地区强阵风的发展。除周围地形影响外，弗劳德数位温梯度约为1.6。

项目成果

期刊论文数量（31）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

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

DOI：
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
影响因子：
0
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

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

DOI：
发表时间：
2005
期刊：
応用力学論文集 Vol.7
影响因子：
0
作者：
内田孝紀;大屋裕二
通讯作者：
大屋裕二

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

DOI：
发表时间：
2005
期刊：
Proceedings of The Sixth Asia-Pacific Conference on Wind Engineering (APCWE-VI) CD
影响因子：
0
作者：
Junji Maeda;Eriko Tomokiyo
通讯作者：
Eriko Tomokiyo

佐賀県でのたつまき災害(2004年6月27日)について

关于佐贺县龙卷灾害（2004年6月27日）