Research on the Pixel-pixel Cross Correlation for the Velocity Distribution Measurement of Two-phase Flow

Xiang Deng, Lihui Peng, Danya Yao, Baofen Zhang

Measurement Science & Electronics Group, Department of Automation, Tsinghua University, 100084, Beijing, P.R.China, xiangdeng@263.net

ABSTRACT

Electrical tomography (ET) provides novel means of visualising the internal behaviour of two-phase flow in industrial process. Using a dual-sensing-plane electrical resistance tomography (ERT) or electrical capacitance tomography (ECT) system, the raw data of two different section images can be acquired synchronously and the two images reflecting the inner medium distribution respectively can also be reconstructed by using imaging algorithm. Further, the analysis of pixel-pixel cross correlation is able to be setup and the measurement of velocity distribution of two-phase flow could be achieved. The principle is described in the paper. The FFT algorithm for grey value computation and cross correlation function calculation is also introduced. Some experimental results of pixel-pixel cross correlation in vertical slug flow are presented.

Keywords Tomography, cross-correlation, velocity measurement, two-phase flow