临界雷诺数下带人工水线斜拉索气动性能研究

通过风洞试验,在临界雷诺数下,研究带上水线拉索模型的气动性能。测得不同风向角下拉索表面风压分布情况,得到作用在拉索模型上的气动力系数,分析临界雷诺数下拉索的气动稳定性。研究表明:基于准定常假定,在临界雷诺数下,拉索发生风雨激振的可能性较亚临界区低;上水线改变了拉索表面的流体分离并出现分离流再附现象,导致拉索气动力随上水线位置的改变而发生剧烈变化。

On aerodynamic characteristics of inclined stay cables with upper rivulet at critical Reynolds numbers

Aerodynamic characteristics of inclined and yawed stay cables with upper rivulet are investigated by wind tunnel tests in the critical Reynolds number regime. The variations of mean wind pressures and aerodynamic forces on the cable model with rivulet positions are obtained at several typical wind angles. Furthermore, the aerodynamic stability of the cable is discussed based on Den Hartog’s criterion. It is found that the aerodynamic characteristics of cables with upper rivulet change drastically when the Reynolds number increases from the subcritical regime to the critical regime. The upper rivulet will affect the flow separation and induce reattachment of separated flow on the upper side of the cable. According to the classical galloping theory, rain-wind-induced vibration of stay cables can still occur at critical Reynolds numbers; however, the possibility of the aerodynamic instability reduces.