为了克服噪声对信号的影响,提出一种利用最大信噪比和相关法测量两相流速度的方法。基于最大信噪比的信号分离方法是一种盲源信号分离方法,该算法利用统计独立信号完全分离时信噪比最大作为分离准则,它具有非常低的计算复杂度。这里首先利用盲源信号分离方法分别提取出上游和下游两相流信号,并据此求出两相流信号的相关函数曲线,由此求出信号的渡越时间,最后给出仿真实验的处理结果。实验结果表明该方法能够满足两相流速度的测量要求。
To overcome the impact of noise on the signal, the essential method for measuring two-phase flow velocity is proposed based on maximal signal noise ratio (SNR) and cross correlation method in this paper. This signal separation method based on maximal signal noise ratio (SNR) is a blind separation algorithm. The character that signal noise ratio (SNR) is maximal when statistically independent source signals are completely separated, is used as a separation criterion. The merit of this algorithm is very low computational complexity. Firstly two-phase flow signals are extracted from output signals of upstream and downstream sensors based on maximal signal noise ratio (SNR), respectively. Then cross correlation curve of two-phase flow signals are obtained on the basis of these results. The transition time is found from this curve. Finally, simulated and experimental results are given. The experimental results show that the method satisfies the need of measurement of two-phase flow velocity.