机动飞行条件下高速转子系统会同时受到环境载荷以及转子自身的共同激励而产生强烈的强迫响应。为研究其复杂的振动特性,本文采用Vold-Kalman滤波(Vold-Kalman Filter,VKF)对不同基础运动激励下转子系统的实测振动信号进行阶次跟踪滤波...机动飞行条件下高速转子系统会同时受到环境载荷以及转子自身的共同激励而产生强烈的强迫响应。为研究其复杂的振动特性,本文采用Vold-Kalman滤波(Vold-Kalman Filter,VKF)对不同基础运动激励下转子系统的实测振动信号进行阶次跟踪滤波。为验证VKF的有效性及参数设置的可靠性,通过转子动力特性计算生成系统响应的仿真信号,并通过加噪处理模拟测量信号,然后通过VKF提取目标阶次的时域波形。通过陀螺运动转子动力学试验,测得不同基础转动激起的系统振动响应,组合使用VKF和计算阶次跟踪(Computed Order Tracking,COT)提取并分离了转子转频信号和基础低频信号的时域和阶次信息。结果表明,单轴滚转或俯仰运动均会激起与其频率一致的低频振动响应,且滚转、俯仰角速度的大小会影响该低频信号的幅值大小;随着基础运动角速度的变化,转子前四阶振动分量没有发生明显的变化,而基础运动频率与转频之间的频带区域有显著变化。此方法有效地提升了机动飞行下转子支承系统振动信号处理与分析的准确度和效率,降低了信号噪声。展开更多
Installing the splitter plates is a passive aerodynamic solution for eliminating vortex-induced vibration (VIV). However, the influences of splitter plates on the VIV and aerostatic performances are more complicated d...Installing the splitter plates is a passive aerodynamic solution for eliminating vortex-induced vibration (VIV). However, the influences of splitter plates on the VIV and aerostatic performances are more complicated due to aerodynamic interference between highway and railway decks. To study the effects of splitter plates, wind tunnel experiments for measuring VIV and aerostatic forces of twin decks under two opposite flow directions were conducted, while the surrounding flow and wind pressure of static twin decks with and without splitter plates are numerically simulated. The results showed that the incoming flow direction affects the VIV response and aerostatic coefficients. The highway deck has poor vertical and torsional VIV, and the VIV region and amplitude are different under different directions. While the railway deck only has vertical VIV when located upstream. The splitter plates can impede the process of vortex generation, shedding and impinging at the gap between twin deck, and significantly reducing the surface fluctuating pressure coefficient, thus effectively suppressing the VIV of twin decks. While, the splitter plates hurt the upstream deck regarding static wind stability and have little effect on the downstream deck. The splitter plates of appropriate width are recommended to improve VIV performances in twin parallel bridges.展开更多
文摘机动飞行条件下高速转子系统会同时受到环境载荷以及转子自身的共同激励而产生强烈的强迫响应。为研究其复杂的振动特性,本文采用Vold-Kalman滤波(Vold-Kalman Filter,VKF)对不同基础运动激励下转子系统的实测振动信号进行阶次跟踪滤波。为验证VKF的有效性及参数设置的可靠性,通过转子动力特性计算生成系统响应的仿真信号,并通过加噪处理模拟测量信号,然后通过VKF提取目标阶次的时域波形。通过陀螺运动转子动力学试验,测得不同基础转动激起的系统振动响应,组合使用VKF和计算阶次跟踪(Computed Order Tracking,COT)提取并分离了转子转频信号和基础低频信号的时域和阶次信息。结果表明,单轴滚转或俯仰运动均会激起与其频率一致的低频振动响应,且滚转、俯仰角速度的大小会影响该低频信号的幅值大小;随着基础运动角速度的变化,转子前四阶振动分量没有发生明显的变化,而基础运动频率与转频之间的频带区域有显著变化。此方法有效地提升了机动飞行下转子支承系统振动信号处理与分析的准确度和效率,降低了信号噪声。
基金Projects(51925808,52078504,51822803) supported by the National Natural Science Foundation of ChinaProject(2022JJ10082) supported by the Natural Science Foundation of Hunan Province,China+1 种基金Project(N2022Z004) supported by the Research on Technology Development Trend and Key Common Problems in Railway,ChinaProject(Xplorer Prize 2021) supported by the Tencent Foundation,China。
文摘Installing the splitter plates is a passive aerodynamic solution for eliminating vortex-induced vibration (VIV). However, the influences of splitter plates on the VIV and aerostatic performances are more complicated due to aerodynamic interference between highway and railway decks. To study the effects of splitter plates, wind tunnel experiments for measuring VIV and aerostatic forces of twin decks under two opposite flow directions were conducted, while the surrounding flow and wind pressure of static twin decks with and without splitter plates are numerically simulated. The results showed that the incoming flow direction affects the VIV response and aerostatic coefficients. The highway deck has poor vertical and torsional VIV, and the VIV region and amplitude are different under different directions. While the railway deck only has vertical VIV when located upstream. The splitter plates can impede the process of vortex generation, shedding and impinging at the gap between twin deck, and significantly reducing the surface fluctuating pressure coefficient, thus effectively suppressing the VIV of twin decks. While, the splitter plates hurt the upstream deck regarding static wind stability and have little effect on the downstream deck. The splitter plates of appropriate width are recommended to improve VIV performances in twin parallel bridges.
