中文摘要：

研究以阻力系数为对象,采用三维数值模拟方法,针对苏通大桥主梁、薄平板及矩形三个典型断面,在逐一验证数值模拟精度的前提下,考察了三个典型断面的总阻力系数与压差阻力系数随风攻角、雷诺数和湍流度的变化规律,分析摩擦阻力对总阻力贡献率（简写为摩擦阻力贡献率）的变化规律,并讨论了这种差异的原因;此外,针对苏通大桥主梁断面,分析了栏杆对摩擦阻力贡献率的影响。研究结果表明：对于三种典型断面,薄平板断面的摩擦阻力贡献率最大,苏通大桥主梁断面的摩擦阻力贡献率稍小,矩形断面的摩擦阻力贡献率几乎可以忽略。三种断面的摩擦阻力贡献率随着风攻角绝对值的增大而减小,其中薄平板断面和苏通大桥主梁断面的摩擦阻力贡献率随着风攻角变化明显,而雷诺数和湍流度变化对三种断面的压差阻力或摩擦阻力的影响很小;与无栏杆的主梁断面相比,有栏杆的苏通大桥主梁断面的摩擦阻力贡献率要下降一半左右。研究结论可为测压方法在工程中的适用性提供参考。

英文摘要：

The Sutong Bridge’s cross section ,flat plate and rectangular cylinder were chosen as the typical sections in this pa‐per ,and the three‐dimensional numerical simulations were carried out under different conditions .The accuracy of the numerical simulation method adopted in the present study is proved .Then the trends of drag coefficient and pressure drag coefficient of the three sections varying with the wind attack angles ,Reynolds number and turbulence were investigated .Meanwhile ,the reasons of their different variations were discussed .Furthermore ,the effects of handrail on the total drag coefficient and pres‐sure drag coefficient of the Sutong Bridge’s girder section were analyzed .The results show that the friction drag of flat plate accounts for the largest proportion of the total drag ,the Sutong Bridge’s girder section comes second ,while the rectangular cylinder is the smallest .For the three typical sections ,the proportions of friction drag in total drag decrease with the increase of wind attack angles ,the Reynolds number and turbulence have a little effects on their friction drags or pressure drags .When the handrails are considered on the Sutong Bridge’s cross section ,the contribution of friction drag to the total drag approxi‐mately decreases to 50% .The conclusions in this paper can provide a reference for the pressure distribution method applied to the engineering practice .