(A) study on flow measurement methods using ultrasonic flowmeter and LDV

Abstract

The main objective of this study is to investigate the velocity profile, which is the key factor of flow-accelerated corrosion, in a circular tube through the experimental work and the computational calculation. Performing the present study, two types of representative non-intrusive measurement methods are picked to carry out more accurate flow velocity profile measurement. First, ultrasonic flowmeter is used to get the line averaged velocity profile. Second, laser doppler velocimetry is selected to find the local point-wise velocity profile in the circular tube centerline. To apply these two methods for the circular tube test section, some correction methods are used in each measurement technique. Computational calculation using CFX code is additionally performed in a given test section. LDV measurement method has a weak point in a circular channel due to curvature and ultrasonic flowmeter has a problem in a small diameter channel. Therefore, code calculation data is used to compare with corrected experimental data in each measurement methods. Moreover, calculated flow velocity profile data is converted to visual forms of vectors, contours and shaded contours with JASPER. The present study shows that ultrasonic flowmeter and LDV can measure local velocity data in a small size circular channel.