For velocity measurements of solid-phase particles in gas-solid two-phase flow
the cross-correlation and adaptive filtering time delay estimation for measuring the velocity are discussed. For the signal outputted by the double-electrode electrostatic sensor installed in pneumatic conveying pipe
the correlation function is adopted to compare the similarity of signals outputted from upstream and downstream electrodes
and the time delay is recorded when the similarity gets the greatest or the relevant function takes the maximum. Combining the distance between electrodes of sensors
the average speed of solid-phase passing the sensors is evaluated
and adaptive filter is also used to calculate the time delay of outputting signal between electrostatic sensors upstream and downstream for obtaining the velocity of solid particles in the pipeline. The experimental results show that the statistic characteristics of measured electrode signal and noise are affected by the environments
so the accuracy of measured speed with the cross-correlation method is greatly reduced.However
the adaptive filter can constantly adjust their parameters according to the relationship between signal and noise to satisfy the least mean square algorithm.
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references
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