Multiresolution Analysis of Tube-wall Pressure Fluctuations Signal in the Static Mizers with wisted Leaves
A study of multi-scales characteristics of tube pressure time series signals in a Kenics static mixer was undertaken using turbulent higher order items and the power spectrum Junction based on wavelet transform. By applying the method of direct determination of the flatness,the amplitudes of Flatness at different scales for turbulent flow have stronger fluctuation and mainly fluctuate between 2.3 to 14.9. It was found that the flatness factors firstly increase then decrease as the frequency bands decreased. Most flatness for the approximations signal,a7,were below 3 which indicated large scale vorticities and steady flow,but the flatness factor of detail signals were above 3 which indicated small scale vorticities and unsteady flow with stronger intermittence especial in the frequency band from 500 Hz to 1000 Hz. Of course,considerably strong coherent structure exists at the tube-wall pressure. The frequency for main energy ofprssure fluctuation is below 2.5 Hz,but more than eighty percent of radial fluctuation energy is below 15.625 Hz.
Indez Terms-static mizer pressure fluctuation time-series analysis flatness.
Huibo Meng Yanfang Yu Bin Gong Jianhua Wu
College of Mechanical Engineering Shenyang Institute of Chemical Technology Shenyang,Liaoning Province,China
国际会议
2009 9th International Conference on Electronic Measurement & Instruments(第九届电子测量与仪器国际会议 ICEMI2009)
北京
英文
1858-1863
2009-08-16（万方平台首次上网日期，不代表论文的发表时间）