Two phase flow visualization in an annular tube by an Electrical Resistance Tomography

Phase distribution within an annular channel is desired to know as precise as possible for industrial processes like cooling system and etc. Electrical Resistance Tomography (ERT) can be used to achieve this task since it is a non-invasive visualization technique. However, the internal structure which forms the annulus with the pipe wall makes the reconstruction of phase distribution different from the conventional application of ERT, especially when the diameter of the internal structure is big. The case of a non-conductive internal structure with the diameter ratio of 0.76 is studied on the electric field distribution and sensitivity distribution. Small bubbles within the annulus and a stratified flow occupied half of the cross section are numerically simulated and reconstructed with one-step Gauss-Newton method which provides good resolution on the bubbles location but overestimates their size.