基于主动格栅脉动流场的抖振力测试与相关性研究

A study on buffeting force test and correlation based on active grid turbulence field

为了探究钝体断面在紊流作用下抖振力的相关性机理,以矩形桥梁断面为例,在主动格栅产生的脉动流场中,通过测压试验并结合不同相关性模型拟合方法,研究了在不同脉动频率下抖振力的空间分布特性。对比探究矩形桥梁断面在静止状态以及运动状态抖振力空间相关性的变化,并利用matlab进一步分解自激力与抖振力,以此来分析自激力对抖振力展向相关性的影响;同时,通过天平测力试验(同步测压)对比了两种不同测力方法的试验结果。试验结果表明抖振阻力跨向相关性伴随着频率和跨向间距的增大而减小,在气动自激力的影响下,抖振力的跨向相关性能得到一定程度的提高,并高于来流脉动风速的相关性。

In order to study the correlation of buffeting forces on a bluff body,a rectangular cylinder was taken as an example.In the pulsating flow field of active grids,a pressure measurement method was applied to study the span-wise buffeting force under turbulent flow,combined with different correlation model fitting methods.The spatial correlation of buffeting force was compared with static and moving states to analyze the influence of the self-excited force on the correlation of the buffeting force,by decomposing the two forces with matlab.Two different force measurement methods(synchronous pressure measurement)were compared by a balance force test.The results show that the span-wise correlation of buffeting force decreases with the frequency and span spacing.Under the influence of aerodynamic self-excited force,the correlation was improved and larger than that of turbulence.