Computational Method of Dielectric Sensor Design for Two-Phase Flow Measurement

The structure design is the major concern in dielectric sensor in two-phase flow analysis. To optimize the design, computational method is used in the electrostatic field analysis with finite-element method. In the finite-element analysis, two electrodes are loaded with different constant voltages. Nodal variable voltage is resolved by the ANSYS Mechanical APDL solver. The stored energy is derived from the electric field intensity. The sensor capacitance is computed from the stored energy. Various sensor structures are examined under different flow conditions. Three rules are found in the process of sensor structure analysis: First, the sensitivity of dielectric measurement has no relationship to internal structure of the dielectric sensor. Second, the sensitivity decreases with the increasing of gap thickness, but the decreasing rate is becoming slow finally. Third the the sensitivity increases with the increasing of gap length, and the increasing rate is constant usually. The optimization design of dielectric sensor is a moderate gap thickness and a maximum gap length with an arbitrary internal structure.