Characteristics of Induced Potential of Electromagnetic Flow Meter

The basic principle of EMF (electromagnetic flow meter) is the Faraday electromagnetic induction law. An induced voltage EMF for measuring flow rate of single phase in pipes has been used successfully in many industrial areas. But the measurement of volumetric flow rate of multiphase flow is not understood poor, especially the measurement of the continuous phase velocity profile in multiphase flows where the continuous phase is electrical conductive. This paper tries to investigate the characteristic of induced electric potential or potential drop, which can reflect the velocity distribution of the conductive continuous phase in the flow pipe. A predefined fluid velocity distribution, v_z=5+200y, that means the component z of fluid velocity varies with the coordinate value of axis y and the components x and y of the fluid velocity are 0, was applied in the investigation. The numerical simulation model with geometry and physical preconditions was built. The analysing methodology adopting multiple virtual electrodes that could be arranged at any position of the internal circumference of fluid pipe to meet the requirement of signals picking for induced potential was proposed. Finally, the characteristics of induced potential that varies with the electrodes position are analysed clearly in different figures