基于大涡模拟的波浪型斜拉索减阻减振研究

Large eddy simulation of flow passing a wavy stayed cable for drag and lift reduction

针对通过改变斜拉索表面形状来减小斜拉索由风载荷引起的振动问题进行研究,运用大涡模拟方法,对两种典型的波浪型斜拉索λ/D=2和λ/D=6的静止绕流特性进行了分析。分析结果表明:在Re=10000时,波浪型斜拉索λ/D=2和λ/D=6均有一定的减阻减振特性,其中斜拉索λ/D=2的减阻减振效果更好,减阻和减振分别能达到30%和90%,这主要是由于波浪型斜拉索沿展向的截面变化,导致流动分离点不同,改变了表面背压分布;斜拉索λ/D=2更好地延缓了剪切层的分离,重新生成稳定的结构,从而较好地抑制了涡脱的形成,具有一定的减阻减振效果。

The changing the shape of stayed cable is studied in this article to reduce vibration response which caused by wind load.Large eddy simulation is applied to analyze the flow characteristics of two type of wavy stayed cable withλ/D=2 andλ/D=6,respectively.The computing results show that the wavy stayed cable ofλ/D=2 andλ/D=6 make a good performance on drag and lift reduction.The wavy stayed cable ofλ/D=2 is better for which the drag and lift reduction is 30%and 90%.The reason is that periodic variation along spanwise direction on wavy stayed cable leads to the change of flow separation point.The formation of more stable structure extends three-dimensional free shear layers separation which changes the pressure distribution on wavy stayed cable ofλ/D=2 and suppresses the formation of mature vortices at further downstream positions.So they have characteristics of drag reduction and lift suppression.