성층류 유동장에서 전기임피던스 단층촬영기법을 이용한 동적 계면 추정 알고리즘 개발

Abstract

In electrical impedance tomography(EIT) array of electrodes are attached on the boundary of an object and small alternating currents are injected through these electrodes, and then the resulting voltages are measured. An estimation for the cross-sectional resistivity distribution of the object or changes in it is obtained by using these current and voltage measurements made on the boundary on a nondestructive manner. This thesis is concerned with the interfacial boundary estimation in stratified flows of two immiscible liquids using electrical impedance tomography. Flows of two immiscible liquids in pipelines are of particular interest in many engineering applications. As a typical example, liquid hydrocarbons transported in pipelines over long distances (for example, crude oil, gasoline, diesel) often contain free water. Knowledge of the binary mixture flow is of importance in the design and operation of such systems. Electrical impedance tomography(EIT) may be a promising method to measure the interfacial boundary in flows of two immiscible liquids because of its non-intrusive characteristics and high temporal resolution. The interfacial boundary os parametrized with front points and the unknown positions of the front points are estimated based on the relationship between the injected currents and the induced boundary potentials. It is assumed that the interfacial boundary moves during the time taken to collect a full set of independent measurement data. In order to find the unknown interface, the front point locations are treated as state variables, which are tracked through the unscented Kalman filter approach. Numerical experiments are successfully conducted for the verification of the proposed approach.