Charcteristics of wind load due to abrupt gust

突发阵风风荷载特征

• 批准号: 06650644
• 负责人: KAWAI Hiromasa
• 金额: $ 0.9万
• 依托单位: Tokyo Denki University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06650644/
• 关键词: Gust; Typhoon; Damage; Conical vortex; Roof tile scatter; Local suction; Change of wind direction; 風向変化; 風荷重

Buildings and houses are often damaged by abrupt gust in a strong wind like a typhoon. Wind suddenly increase to double or triple of a ordinary speed and then decrease gradually in several seconds in such a gust. However, such a abrupt gust wind load is not described in codes of practice in any country in which it is assumed that wind blows stationary in a retativery long time. In this research, effects of the abrupt gust on wind load on a house are investigated by wind tunnel tests mainly from the following two points of view.1) To simulate an abrupt gust in a wind tunnel2) To clarify a mechanism of a wind loading due to the gust.In order to simulate the gust, we set a fence at a position far from a house model with a flat roof. By adjusting a hight of the fence and the distance from the model, an abrupt gust can be produced, which is very similar to the gust in a natural wind. The flow on the roof is influenced significantly and the wind load on the roof suddenly changed by passing the gust. The separated shear layr swept by the gust to produce a very severe local suction on the laeding edge of the roof. In the case of oblique flow, a conical vortex is formed on the roof and flaps in a short time by the abrupt increase of wind speed and a variation of wind direction.

建筑物和房屋通常会像台风一样在强风中突然破坏。风突然增加到普通速度的两倍或三倍，然后在这种阵风中逐渐减小。但是，在任何一个国家，假定风能在长时间转移的情况下吹来静止的国家，这种突然的阵风量均未描述。在这项研究中，突然的阵风对风负荷对房屋的影响，主要是从以下两个角度来看的。由于阵风，为了模​​拟阵风，我们将围栏设置在远离带有平坦屋顶的房屋模型的位置。通过调节围栏的高峰和与模型的距离，可以产生突然的阵风，这与自然风中的阵风非常相似。屋顶上的流动受到显着影响，屋顶上的风负载突然通过阵风改变了。分离的剪切层被阵风扫过，在屋顶的衣服边缘产生了非常严重的局部吸力。在倾斜流动的情况下，屋顶上形成了圆锥形涡流，并在短时间内通过风速的突然增加和风向变化而在短时间内襟翼。

项目成果

H.Kawai: "Structure of conical vortices related with suction flucuation" Journal of Wind Engineering and Industrial Aerodynamics. (1996)

H.Kawai：“与吸力波动相关的圆锥形涡流的结构”风工程和工业空气动力学杂志。

H.Kawai,: "Characteristics of fluctuaing suction and conical vortices" Journal of Wind Engineering and Industrial Aerodynamics. (1996)

H.Kawai，：“脉动吸力和锥形涡流的特征”风工程和工业空气动力学杂志。

H.Kawai: "Structure of conical vortices related with suction fluctuation" Journal of Wind Engineering and Industrial Aerodynamics. (1996)

H.Kawai：“与吸力脉动相关的圆锥形涡流的结构”风工程与工业空气动力学杂志。

H. Kawai: "Structure of conical vortices related with suction fluctuation" Journal of Wind Engineering and Inducstrial Fluid Dynamics. (発表予定). (1996)

H. Kawai：“与吸力脉动相关的圆锥形涡流的结构”《风工程与工业流体动力学杂志》（即将出版）。

河井宏允: "陸屋根上の円錐渦の構造" 日本風工学会誌. 第63号. 113-114 (1995)

Hiroyuki Kawai：“平屋顶上的圆锥形涡流的结构”日本风工程学会杂志第 63. 113-114 (1995)。