Electrical Resistance Tomography Technology And Its Study On Detect Two-phase Flow In Microchannel

With the rapid developent of Micro-electromechanical-System (MEMS) technologytwo-phase flow in microchannel has attacted the interest of a broad number of researchersin the past decades. At present, some optical measuring methods have been used tovisualize the two-phase distribution in microchannel. But their inherent optical scatteringproblem will becomes even more severe within the micro dimension. Therefor, theapplication of promising electrical resistance tomography (ERT) to detect two-phase flowin microchannel was researched in this article.Based on the principle of electrical resistance tomography, the mathematical modelof ERT used to detect the two-phase flow in microchannel was analysed. The forwardproblem of ERT system was solved employing the finite element method (FEM), and thesteps of solution were given. A simulation experiment using COMSOL Multiphysics3.5awas done to prove the basic principle of ERT.According to the inverse of electrical resistance tomography technology solvingmethod, several familiar image reconstruction algorithms were analysed and compared.The advantages and shortages of every algorithm were explained. An image reconstructionalgorithm called Unscented Kalman Filter regularization algorithm was proposed whichwas high-precision and suitable for the detection of two-phase flow in microchannel.A set of Agilent34980A as the core of two-phase flow detection system inmicrochannel was designed. System component and their function in the system ofelectrical resistance tomography were introduced. The model of contact impedancebetween the electrodes and two-phase flow in microchannel was researched. Somemethods to reduce the affect of contact impedance were found.A solid-liquid two-phase flow detection experiment was done using the two-phaseflow system in microchanne. The images of two-phase flow distribution on everycross-section were reconstructed based on the voltages measured by Agilent34980A andUnscented Kalman Filter regularization algorithm. Then the visualization measurementwas realized. The experiment proved that ERT technology can be used to detect two-phase in microchannel.