水下自激吸气式脉冲射流装置瞬时冲击力分解  

Instantaneous impact force decomposition of underwater self-excited inspiration pulse jet device

作　　者：于晓龙 刘新阳 徐洪增 陈豪 汪顺生 高传昌 YU Xiaolong;LIU Xinyang;XU Hongzeng;CHEN Hao;WANG Shunsheng;GAO Chuanchang(Engineering Construction Center,Yellow River Shandong Bureau,Jinan 250011,China;Water Resources and Electric Power,North China University,Zhengzhou 450045,China)Abstract:)

机构地区：[1]山东黄河河务局工程建设中心,济南250011 [2]华北水利水电大学水利学院,郑州450045

出　　处：《振动与冲击》2019年第24期227-234,282,共9页Journal of Vibration and Shock

基　　金：国家自然科学基金(51309099)

摘　　要：为了提取水下自激吸气式脉冲射流装置瞬时冲击力中的时变冲击力和脉动冲击力。运用离散正交小波变换和经验模态分解(EMD)对装置瞬时冲击力进行消噪和分解,确定离散正交小波变换提取时变冲击力的小波基函数和分解层数以及EMD提取时变冲击力的固有模态函数(IMF)个数,分析围压对时变冲击力脉冲幅值和脉冲周期以及脉动冲击力脉动强度的影响规律。结果表明:在不同围压下,离散正交小波变换对时变冲击力的提取效果要优于EMD,但小波基函数的选择需要考虑不同围压下瞬时冲击力的变化特点;围压对装置吸气后时变冲击力脉冲周期影响不大,但对脉冲幅值影响较大;围压和吸气对瞬时冲击力时均值和脉动冲击力脉动强度影响较大,但在不同围压下吸气对两者的影响规律有所不同。In order to study the time-varying impact and fluctuation impact force in the instantaneous impact force of the underwater self-excited inspiration pulsed jet device,discrete orthogonal wavelet transform and EMD were used to denoise and decompose for the instantaneous impact force of the device.The wavelet basis function and the number of decomposition layers for the wavelet transform and the number of intrinsic mode functions(IMF)for EMD were determined for time-varying impact force extraction.The influence of confining pressure on the pulsed amplitude and pulsed period of the time-varying impact and the fluctuation strength of fluctuation impact were analyzed.The results show that under different confining pressure,the discrete orthogonal wavelet transform is better than EMD in extracting the time-varying impact force,but the choice of wavelet basis function needs to consider the variation characteristics of instantaneous impact force under different confining pressure.Confining pressure has little effect on the pulsed period of the time-varying impact force after the device inspiration,but it has a great influence on the pulsed amplitude.Confining pressure and inspiration have a great influence on the time-varying value of the instantaneous impact force and the fluctuation strength of the fluctuation impact force,but the influence of the inspiration on the two is different under different confining pressure.

关 键 词：水下 自激吸气 脉冲射流 瞬时冲击力 离散正交小波变换 经验模态分解(EMD) 

分 类 号：TV131.2[水利工程—水力学及河流动力学]