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采用动网格技术针对低雷诺数(Re=100)下三维波浪型斜拉索在均匀来流中横向受迫振荡问题进行了数值模拟分析。引入直拉索做对比,探讨低雷诺数下不同波浪形状波长参数(λ/D_m为2、6)时三维波浪型斜拉索在特定的振荡振幅(A/D_m=0.2)及不同的振荡频率(fe/fs为0~2)下,其表面所受作用力、尾流流动结构和锁定区间振动响应的变化规律。研究结果表明:λ/D_m=2波浪型斜拉索类似于直拉索,在一定振荡频率范围内(fe/fs为0.9~1.22)同样会发生“锁定”现象,有一定的抑振效果,但没有明显的减阻效果;λ/D_m=6波浪型斜拉索在该区域仍是自然频率起主导作用,其脉动升力系数趋近于0.1,具有非常明显的减阻效果(减阻幅度可达25%),说明波浪型斜拉索三维表面形状的改变可直接影响其表面作用力、尾流流动模式转换及锁定等现象,特定形状的波浪型斜拉索能明显减阻且抑制其锁定区间的振动诱导。
The dynamic grid technique is used to simulate the transverse forced oscillation of a three-dimensional undulating cable in a uniform flow with low Reynolds number (Re = 100). In order to find out the relationship between the specific vibration amplitude (A / D_m = 0.2) and the different oscillation frequency when the wave number of different wave shapes (λ / D_m is 2, 6) (fe / fs is 0 ~ 2), the variation of the surface force, wake flow structure and the vibration response of the lock-in zone are studied. The results show that the λ / D_m = 2 wave type stayed cable is similar to a straight cable, and the “lock-in” phenomenon occurs in a certain oscillation frequency range (fe / fs is 0.9-1.22) However, there is no significant drag reduction effect; λ / D_m = 6 wave stayed cable is still dominated by natural frequency in this region, and its pulsating lift coefficient approaches 0.1, which has a very significant drag reduction effect Amplitude up to 25%), indicating that the change of the three-dimensional surface shape of the wave-type stay cables can directly affect the surface forces, wake flow patterns and locking phenomenon. The wave-shaped stay cables with specific shapes can significantly reduce drag and suppress Its locking range is induced by vibration.