【摘要】 在利用空间滤波和电容传感器测量两相流速度时,需要准确测量电容传感器输出信号的带宽。针对此问题提出一种利用经验模态分解算法来测量传感器带宽的方法。文章首先介绍电容传感器的空间滤波效应和经验模态分解的基本原理,并给出固体速度和电容传感器输出信号带宽之间的关系。然后将经验模态分解和平滑滤波器结合对测量信号进行平滑处理,测量处理后的信号带宽,利用带宽计算得到两相流的速度,最后进行了仿真实验,由此方法得到的测量误差都在2%以内,这比利用小波变换方法得到的相对误差要小得多。仿真实验结果表明该方法能够对两相流速度进行比较准确地测量,这也证明了该方法的可行性与有效性。更多还原

【Abstract】 The band-width of the output signal from capacitance sensor needs accurate measurement when measure the velocity of two-phase flow by spatial filter and capacitance sensor.So a method for measuring the band-width of the output signal from capacitance sensor using empirical mode decomposition is proposed in this paper.Firstly,spatial filtering effect of capacitance sensor and the basic principle of empirical mode decomposition are studied;the relationship between solid velocity and band-width of the output signal from capacitance sensor is given.Secondly,the signal is processed by empirical mode decomposition and smoothing filter,then the band-width of signal is found.With the help of the band-width,the velocity of two-phase flow can be computed.Finally,the simulation experiment results are given.The measurement relatively errors obtained by the method in this paper are all less than 2%.These measurement errors are significantly smaller than the ones obtained by wavelet transform.The simulation experiment results have shown that velocity of two-phase flow can be well obtained by the method in this paper,this has also verified the effectiveness and feasibility of this method.更多还原