大跨度空间结构抗风分析的数值风洞方法

数值风洞方法可为复杂形体结构的风压分布确定和结构风振系数选取等提供非试验性的依据。基于计算流体动力学理论,以空间结构为对象,研究数值风洞技术。数值模拟了不同空间结构形体表面及其周围的风场,计算了结构风载体型系数,并与风洞模型实验成果比较,验证数值风洞计算结果的正确性。研究了因其他结构物存在引起的结构风场和结构体型系数变化,探讨了用数值风洞模拟技术鉴别风洞模型试验可能存在的误差及其原因。基于结构表面等压线划分结构受风区域,并以面积加权平均计算得到区域体型系数。还分析了结构多风向角下的结构风载体型系数。

NUMERICAL WIND TUNNEL TECHNIQUE FOR THE WIND RESISTANCE ANALYSIS OF LONG SPAN SPATIAL STRUCTURES

Based on Computational Fluid Dynamics (CFD), the numerical wind tunnel technique (NWTT) is studied, which is effectively applied to the investigation of the wind pressure distribution of complicated structural shapes. The wind fields around and close to structural surface and the wind-load shape coefficients were calculated. Some comparisons between numerical results and wind tunnel model test data were carried out. The changes of the wind-load shape coefficients and wind fields around the structures caused by other structural system were analyzed, and the possible errors and their reasons of the wind tunnel model test were discussed by means of the NWTT. Based on the wind pressure contours or constant value line of wind-load shape coefficients, the sub-areas subjected to different wind actions were plotted and the local wind-load shape coefficients corresponding to these sub-areas were obtained in terms of area weighted average strategy. Additionally, the wind-load shape coefficients under different wind angles were analyzed.