三角形格构式塔身体型系数及屏蔽特性研究Study on shape coefficient and shielding effects of triangular latticed tower body

为满足高压／特高压输电铁塔风致倒塌问题对铁塔体型系数的精准度需求，研究了完全结构化多块网格对格构式三角形输电塔塔身流场的模拟能力，探讨了不同规范体型系数对某铁塔的适用性，并分析了塔身杆件复杂流动干扰作用下的屏蔽特性。结果表明，数值模拟与风洞试验的体型系数吻合很好；完全结构化网格能高保真、高度正交地对铁塔塔身这类复杂空间桁架流场进行离散；《英国杆塔荷载规范》的规定结果虽偏于保守，但其趋势最为接近真实值；在塔身桁架结构各个杆件之间流动干扰作用下，角钢弯折角朝向来流比背向来流的屏蔽作用更强；斜材弯折角背向气流和竖向辅助材弯折角朝向气流的组合之间的流动干扰，使得其对气流的屏蔽作用最强。

Study on shape coefficient and shielding effects of triangular latticed tower body

The crash down of transmission towers demands improved accuracy in wind load designing of ultra‐high voltage transmission lines .Accounting to high fidelity simulation of flow around transmission tower ,the applicability of fully structured multi‐block grids for a triangular latticed tower section model is investigated by solving Navier‐Stokes equations enclosed by k‐εturbulence model ,shape coefficients from different standards are compared under designing tower ,and shielding effects of this section model with complex flow interference are investigated .The results indicated that ,fully‐structured multi‐block grids exhibit high orthogonality and conform well of this complex lattice tower section model ;《BS8100》gives conservative shape coefficients while these coefficients show similar trend comparing to both wind tunnel and numerical results ;Induced by flow interferences among angle‐steel trusses ,the angle‐steel bending forward shields much more seriously comparing to that bending leeward ;the combination of leeward bending diagonal member and forward bending vertical bracing member ,which induce flow interference between themselves ,results in the most serious shielding performance .