超规范高宽比矩形烟囱风压分布与风致响应

Wind pressure distribution and wind-induced response of hyper-norms height-width ratio rectangular chimney

以国内某拟建核电站超规范矩形烟囱为研究对象,建立六种不同高宽比和长宽比结构模型,通过大涡模拟方法获取烟囱周边风压分布特性并开展了有效性验证,对比分析了六种方案下超规范矩形烟囱压力场、速度场和斯托罗哈数变化规律,总结了烟囱顶部扭转角和横风向位移的变化规律并给出风振系数取值。研究表明,超规范矩形烟囱自振频率整体近似呈对数增长趋势;烟囱顶部负压范围和阻力系数均随高宽比和长宽比的增大而减小;烟囱扭转角及其风振系数随高宽比和长宽比变化较小;烟囱横风向风振系数远大于顺风向,应以风振系数较大的横风向位移为目标考虑烟囱横风向风振。研究结果可为此类超规范矩形结构风荷载设计取值提供科学依据。

Taking the hyper-norms rectangular chimney of a proposed nuclear power plant in China as the research object,six structural models with different height-width ratio and length-width ratio are established.The wind pressure distribution characteristics around the chimney are obtained by LES method,and the effectiveness is verified.The variation laws of pressure field,velocity field and Strouhal number of hyper-norms rectangular chimney under the six schemes are compared and analyzed,The variation laws of torsion angle and cross wind displacement at the top of chimney are summarized,and the value of wind vibration coefficient is given.The results show that the natural frequency of the rectangular chimney increases logarithmically as a whole;The negative pressure range and resistance coefficient at the top of chimney decrease with the increase of height-width ratio and length-width ratio;The torsional angle and wind vibration coefficient of the chimney change little with the height-width ratio and length-width ratio.The wind vibration coefficient in the cross-wind direction of the chimney is much larger than that in the downwind direction,and the cross-wind displacement of the chimney with a larger wind vibration coefficient should be considered as the target of the chimney cross-wind wind vibration.The research results can provide a scientific basis for the wind load design of this kind of hyper-norms rectangular structures.