Author/Authors :
Nor Ayob, Nor Muzakkir Universiti Malaysia Perlis - School of Mechatronic Engineering - Tomography Imaging Research Group, Malaysia , Fazalul Rahiman, Mohd Hafiz Universiti Malaysia Perlis - School of Mechatronic Engineering - Tomography Imaging Research Group, Malaysia , Zakaria, Zulkarnay Universiti Malaysia Perlis - School of Mechatronic Engineering - Tomographic Imaging Research Group, Malaysia , Yaacob, Sazali Universiti Malaysia Perlis - School of Mechatronic Engineering - Tomography Imaging Research Group, Malaysia , Abdul Rahim, Ruzairi Universiti Teknologi Malaysia - Faculty of Electrical Engineering - Control and Instrumentation Engineering Department, Process Tomography Research Group (PROTOM), Malaysia , Manan, Mohd Rizal Universiti Malaysia Perlis - School of Mechatronic Engineering - Tomography Imaging Research Group, Malaysia
Abstract :
Simulative studies are done on the use of cross–correlation technique based on a dual–plane ultrasonic transmission tomography for liquid and gas two–phase flow measurement. This technique is used to correlate the signals from each sensing area namely downstream plane and upstream plane. Separation distance between both sensing areas is fixed. The result from cross correlating the dual–plane signals, combined with the known separation distance and the system’s acquisition rate is used to estimate the velocity of the flow inside the investigated process column. Combining Ultrasonic Transmission Tomography (UTT) with the cross–correlation flow measurement technique can provide more information on the flow than a single–plane UTT system. This paper focuses on the mean value of the images and the 2D correlation coefficient that is used to cross–correlate the tomogram images between the downstream and upstream plane of the simulated dual–plane ultrasonic transmission tomography system. The principle of measurement for local gas velocity distribution in a bubbly gas/liquid pipe flow based on crosscorrelation of two plane images is also described. Initial experimental results illustrate the feasibility of the method presented here.
Keywords :
Cross–correlation , frozen pattern , mean correlation , dual–plane simulation , ultrasonic transmission tomography
