Aerodynamic effects on a high slenderness concrete chimney

Abstract This paper presents the results of a theoretical-experimental study on the aerodynamic behavior of a 150m high, slenderness 30, concrete chimney. For the wind tunnel tests two scaled models were built: one rigid for the measurement of the external pressures, and other aeroelastic, in which the main dynamic characteristics of the real structure were reproduced. The dynamic response under atmospheric turbulence (along-wind direction) is described in the paper and is compatible with the methodology of the Brazilian wind code NBR-6123. A brief analysis of the transversal response due to vortex shedding is presented according to the Canadian Wind Code NBCC. It is observed that, due to the low frequency of the structure, the dynamic approach leads to results significantly larger than those obtained from applying the conventional static approach of gust wind speed. The presence of the neighborhood have increased the loads on the structures.

摘要 本文针对一座高度150米、长细比为30的混凝土烟囱的气动特性开展理论与试验结合研究，并报道相关研究成果。本次风洞试验共制作两个缩尺模型：其一为刚性模型，用于测量结构外壁风压；其二为气动弹性模型，可复现原型结构的主要动力特性。本文阐述了该结构在大气紊流作用下（顺风向）的动力响应，其结果与巴西风荷载规范NBR-6123的分析方法兼容。此外，本文还依据加拿大风荷载规范NBCC，对由涡脱落引发的横风向响应展开简要分析。研究发现，由于该结构自振频率较低，动力分析方法得到的结果显著大于采用传统阵风风速静力方法所得的结果。周边建（构）筑物的存在增大了该结构所承受的荷载。