缆索承重桥并列索平均气动性能的雷诺数效应

发布时间：2018-04-30 17:01

本文选题：缆索承重桥 + 并列索　；参考：《工程力学》2017年03期

【摘要】：近距离并列吊索和并列斜拉索在大跨度缆索承重桥中有广泛的应用,但目前在计算并列索静力风荷载时只考虑顺风向阻力的影响,没有考虑因尾流干扰所产生的横风向升力的作用。通过风洞试验,在雷诺数Re=0.9×105~4.6×105(涉及亚临界雷诺数区和临界雷诺数区)研究了多种不同相对位置的并列双圆柱的平均阻力、平均升力和斯特罗哈数随雷诺数的变化规律。研究结果表明:并列圆柱的平均气动性能有强烈的雷诺数效应,临界雷诺数下的气动力系数与亚临界区有很大的差异;在临界雷诺数区域,下游圆柱的平均升力系数会随雷诺数的增大发生不连续突变,这种气动力的突变很可能与双圆柱绕流场的流态结构的演变有关;受上游圆柱的尾流干扰,在临界雷诺数区域内下游圆柱的平均升力系数可达到1.25以上,远大于下游圆柱的平均阻力系数,因而在计算并列索静力风荷载时有必要考虑横风向平均升力的作用。
[Abstract]:Parallel slings and cable-stayed cables are widely used in long-span cable-bearing bridges, but at present only the effect of downwind resistance is considered in calculating the static wind loads of parallel cables. The effect of cross-wind lift caused by wake disturbance is not taken into account. Through wind tunnel tests, the average drag, mean lift and Stroha number of parallel double cylinders with different relative positions are studied at Reynolds number Re=0.9 脳 1054.6x105 (involving subcritical Reynolds number region and critical Reynolds number region). The results show that the mean aerodynamic performance of parallel cylinders has a strong Reynolds number effect, and the aerodynamic coefficients at critical Reynolds number are very different from those in subcritical region, and in the critical Reynolds number region, The mean lift coefficient of the downstream cylinder changes with the increase of Reynolds number. The abrupt change of the aerodynamic force is probably related to the evolution of the flow state structure around the flow field of the double cylinder, and is disturbed by the wake of the upstream cylinder. In the range of critical Reynolds number, the average lift coefficient of the downstream cylinder can reach above 1.25, which is much larger than the average drag coefficient of the downstream cylinder, so it is necessary to consider the effect of the mean transverse wind lift in calculating the static wind load of the parallel cable.
【作者单位】：上海大学土木工程系;石家庄铁道大学风工程研究中心;河北省大型结构健康诊断与控制重点实验室;
【基金】：上海市自然科学基金项目(14ZR1416000) 上海市教委科研创新项目(14YZ004) 河北省杰出青年科学基金项目(E2014210138) 国家自然科学基金项目(51578330)
【分类号】：U441.3

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