A Combined Numerical-Experimental Study on the Noise Power Spectrum Produced by an Electromagnetic Sensor for Slurry Flow

The signals generated by electromagnetic flow sensors used for slurry fluids are often affected by noise interference produced by interaction with the slurry itself. In this study, the power spectrum characteristics of the signal are studied, and an attempt is made to determine the relationship between the characteristics of the related noise and the velocity and concentration of the slurry fluid. Dedicated experiments are conducted and the related power spectrum curve is obtained processing the signal measured by the sensor with Matlab. Numerical simulations are also carried out in the frame of an Eulerian approach in order get additional insights into the considered problem through comparison with the experimental results. The following conclusions are drawn: (1) The intensity of noise is directly proportional to the number of solid particles colliding with the electrode of the electromagnetic flow sensor per unit time, and to the square of the average velocity of the flow layer near the pipe wall. (2) With an increase in the slurry noise intensity, the power spectrum curve shifts upward in the logarithmic coordinate system (and vice versa).