三角形格构式塔身杆件风荷载及流动干扰特性

针对输电塔结构精细设计及优化设计对杆件风荷载准确输入的要求，选用完全结构化的多块网格，通过求解N-S方程得到了不同风向角条件下的三角形塔身节段模型流场并利用风洞试验对其体型系数进行验证．与各国规范的对比分析表明，《英国杆塔荷载规范》可用于相关设计工作；分析了不同杆件风荷载随风向角变化的成因，指出了迎风面积变化主导了最上游主材的风荷载特性，而其它两根主材的风荷载同时受到迎风面积变化及上游杆件流动干扰的影响；利用不同高度、不同展向位置的截面流线方法研究了塔身节段模型杆件之间的流动干扰性态，结果表明，如下四种流动干扰行为共同决定了节段模型的杆件风荷载特性：a）相互独立的流动干扰杆件群；b）屏蔽作用；c）两组独立的斜置阵列的流动干扰作用；d）尾迹干扰作用．

Wind Load Characteristics of Triangular Latticed Tower Trusses and Flow Interferences in-between Them

To meet the needs for accurate wind loads of trusses in precise design as well as the optimization of transmission towers, Navier-Stokes equations were employed in numerical simulations of triangular tower section model based on multi-block structured grids. Shape coefficients at different wind angles were obtained and validated by the results from wind tunnel tests. Comparing with the shape coefficients from different standards and codes, it was indicated that, BS8100 is applicable in practical design; The nonlinear variation of truss wind loads at different wind angles was discussed, and it was shown that windward area acts as the most important parameter for wind loads of the main member located at the forefront position, while both wind area and flow interference work together for wind loads of the other two main members; streamlines at different heights and different semi-span locations, were adopted in the study of flow interferences in-between truss members, and it was found that four flow interference behaviors codetermine the complex flow fields around triangular section model consisting of angle-steel trusses: a) flow interferences limited in different groups; b) shielding effects; c) flow interferences induced by two oblique arrays; d) wake flow affecting downstream truss flows.