流线型桥梁断面雷诺数效应

Reynolds number effect of streamlined bridge section

采用数值模拟方法计算了不同雷诺数苏通桥流线型断面三分力系数,通过风洞试验研究了宽高比为10∶1的流线型桥梁断面的雷诺数效应,分析了雷诺数对阻力系数、表面压力系数、风压功率谱及斯特罗哈数的影响,研究了粗糙度对雷诺数效应的抑制作用。分析结果表明:阻力系数随雷诺数的增大而减小,雷诺数会改变表面压力系数0值出现的位置,斯特罗哈数对雷诺数有平台区存在,低雷诺数风洞试验测得的斯特罗哈数比实桥值小20%,因此,流线型桥梁断面存在明显的雷诺数效应,且粗糙度对雷诺数效应有抑制作用。

The three-component force coefficients of streamlined sections of Sutong Bridge with different Reynolds numbers were calculated by using numerical simulation.The Reynolds number effect of streamlined section for bridge model with chord/thickness ratio of 10∶1 was investigated by wind tunnel test,the influence of Reynolds number on drag coefficient,surface pressure coefficient,wind pressure spectrum and Strouhal number was analyzed,and the restraining action of surface roughness on Reynolds number effect was researched.It is pointed that drag coefficient decreases with the increase of Reynold number.The zero position of surface pressure coefficient is subject to the influence of Reynolds number.Strouhal number exists platform effect because of the influence of Reynolds number.Strouhal number measured by wind tunnel test with low Reynolds number decreases by 20% compared with the one of practical bridge.Reynolds number effect of streamlined section is considerable.Surface roughness can restrain Reynolds number effect.9 figs,15 refs.