广播电视发射塔绕流场及表面风压特性分析

Analysis on Flow Field and Surface Wind Pressure Characteristics of Television Tower

本文基于CFD数值模拟平台Fluent,采用完全结构化网格,选用SST k-ω湍流模型对广播电视发射塔的外流场进行了模拟,得到发射塔的绕流场和表面风压分布。对比风洞试验的表面风压系数,数值模拟结果除了部分测点在纬向角90°附近的压力系数相差较大外,其余位置与试验结果基本吻合。通过对流场迹线图分析研究,发现发射塔各圆台塔段均发生了不同程度的流动分离。基于发射塔的表面风压分布,得到了数值模拟各测点位置的体型系数,其值与高耸规范取值很匹配,较风洞试验结果偏安全。对于类似结构电视塔的初步设计或既有结构核算,可采用CFD模拟获取其风荷载计算参数。

Based on the CFD simulation platform Fluent the fully structured grid and the SST K-ωturbulence model were used to simulate the outflow field of the television tower in this paper and the flow field around the transmission tower and the surface wind pressure distribution were obtained.Compared with the surface wind pressure coefficient of wind tunnel experiment the results of numerical simulation were in good agreement with the experimental results except that the pressure coefficient of some measuring points near 90°latitude angle was quite different.Through the analysis of the trace diagram of the convection field it could be found that the flow separation occurs in different degrees in each tower section of the television tower.Based on the distribution of surface wind pressure the shape coefficients of each measuring point were obtained which matched the standard value and was safer than the wind tunnel test result.CFD simulation would be used to obtain the wind load calculation parameters for the preliminary design or existing structural accounting of similar television Tower.