Application of Electrical Capacitance Tomography to the Visualization of Debris Flow

Zhiying Chena, Peijuan Lia, Lei Zhoua, Shi Liub,*

aSchool of Energy and Power Engineering, North China Electric Power University, Beijing, 102206, China

bSchool of Control and Computer Engineering, North China Electric Power University, Beijing, 102206, China,email: liushi_ncepu@yahoo.com.cn

ABSTRACT

Debris flow is an important mechanism for transporting large volumes of sediments on the land as well as in the water. Due to the inaccessible and hazardous environment often associated with debris flow, surface observation and laboratory experiments measuring fluid property factors played an important role in the study of these phenomena. In this paper, experimental studies are reported on image reconstruction and velocity measurement in a sub aqueous debris flow, using electrical capacitance tomography (ECT). Being different from the conventional methods, ECT is a unique measuring technique with great potential in multiphase flow measurement. ECT is non­invasive and aimed at the visualization of the cross­sectional permittivity distribution of a dielectric object based on the measured capacitance data. In this experiment 8­8 electrodes are selected for the ECT sensor that is glass­ walled and acted as the fluid conduit. The cross­correlation method is applied to the calculation of the velocity of the debris flow. The measurement results are confirmed by computational fluid dynamics (CFD) analyses and the reconstructed images of the debris flow distributions are compared with the simulation results, which verifie the feasibility and reliability of ECT as an advanced technique for monitoring the debris flow.

Keywords Electrical capacitance tomography, Visualization, Debris flow, Two­phase flow, Simulation