斜交布置孪生大跨屋盖结构风干扰效应研究

建筑物的风干扰问题具有一定的复杂性,针对复杂外形结构的风干扰效应问题,文章以2个斜交布置的孪生大跨屋盖结构为研究对象,通过风洞试验对比了独立模型状态和有干扰模型状态下各工况风压分布特征的差异,分别统计和分析了平均风压分布、顶面吸力及局部负极值风压系数的规律和特性,研究结果表明孪生大跨屋盖结构具有明显的风干扰效应。

周边建筑对在建超高层塔楼的风场干扰效应研究

针对建筑风环境的研究主要集中于建筑形态抗风设计,在数值模拟方面多聚焦于建筑场地通风效果研究,而针对建筑表面幕墙风压和施工过程中的建筑风压研究则相对较少。因此,以上海市某超高层塔楼为研究对象,从城市建筑轮廓图提取周边建筑数据建立数值模型,对目标单独建筑模型和建筑群模型2种工况的8个风向进行CFD模拟,以研究周边建筑对超高层施工的风场干扰效应。结果表明:在低高度处,低矮建筑密集,遮挡效应对目标建筑风场削弱较为明显;而中间以上高度,目标建筑在多个方向受邻近超高层的遮挡效应和峡谷效应干扰严重,负压出现明显增幅。

Wind?Induced Interference Effect Between Newly?Built Cooling Tower and Existing Cooling Tower

Disturbance effect is one of the important factors for wind damage to large cooling towers.Existing studies on the wind-induced interference of cooling tower groups are aimed at the same size and the lack of wind-induced interference effects between cooling towers of different sizes.With the background of the additional cooling tower project at Shandong Luxi Power Plant in China,the rigid body pressure wind tunnel test is carried out to obtain 194 conditions for the three combinations of the existing four-tower combination(small size),the new two-tower combination(large size)and the six-tower combination surface wind pressure distribution.Numerical simulation of the surrounding flow field of the cooling tower group with the most unfavorable interference condition of the six-tower combination is conducted using the computational fluid dynamics(CFD)method.Based on this,the characteristics of the average and pulsating wind pressure distribution of the cooling tower surface under the six-tower combination are mainly studied,and the load interference coefficients of the large-sized cooling tower and the small-sized cooling tower under the three tower group combinations are compared.The velocity flow field and vorticity changes around the cooling tower group at unfavorable wind angles are analyzed,and the wind-induced interference mechanism between cooling tower groups of different sizes is mainly refined.Research shows that the interference effect between such cooling tower groups of different sizes is much larger than that of cooling tower groups of the same size,which is specifically manifested as the enhancement effect of small-sized cooling towers and the shielding effect of large-sized cooling towers.The interference coefficient of large-sized cooling tower groups increases by 28%,and the interference coefficient of small-sized cooling tower groups decreases by 6.4%.The airflow acceleration caused by the pinch effect between small-sized cooling tower groups has an adverse effect on large-sized cooling towers and can significantly increase the magnitude of local wind load.The shielding effect of large-sized cooling towers can reduce the overall wind load of small-sized cooling towers.The research conclusions can provide the basis of wind load value design for wind resistance design of such large cooling tower addition projects.

Wind tunnel study of aerodynamic wind loading on middle pylon of Taizhou Bridge

Segment sectional model tests are carried out to investigate the wind loading on middle pylon of Taizhou Bridge, which has complicated three-dimensional flow due to its feature of double columns. Through the force measuring tests, aerodynamic force coefficients of every segment of the pylon columns have been obtained. It is found that the tested aerodynamic force coefficients are much smaller than those given by codes. The interference effects of aerodynamic force coefficients between columns of pylon are discussed. The results show that the interference effect is the most evident when the yaw angle is about 30 ° from transverse direction. This kind of interference effect can be described as diminutions in transverse aerodynamic force coefficients and magnifications in longitudinal aerodynamic force coefficients of downstream columns.

凉都体育中心体育馆屋盖CFD数值分析

采用计算流体力学软件Fluent得到凉都体育中心体育馆屋盖的风压力分布,进而得出体育馆屋盖的风压系数分布.对建筑间风遮挡效应进行了讨论,两体量相近的建筑物相邻时,下游建筑受到的风荷载往往更为不利.屋盖在风荷载作用下受向上的风吸力,屋盖不同位置的风压系数都不相同,且分布规律复杂,为简化设计计算过程,建议凉都体育馆屋盖体型系数可取为-0.9.