THE overall performance of the ultrasonic flowmeter is dependent on flow profiles due to the meter installation.The practical limitations of industry sites, space constrains,and various upstream pipe configurations may result in the flow field on the measurement section not fully developed or even seriously distorted and the meter’s readings erroneous [1], [2]. Hilgenstock and Ernst [3] compared the changes the ultrasonic flowmeter behavior downstream of the specific
pipe configurations. At different positions and circumferential angles, the error of the ultrasonic flowmeter exposed to the downstream flow of two typical installations in piping systems with a single-elbow and an out-plane double-elbow, were experimentally identified [4]. One method of reducing the affect of flow profile is using multipath ultrasonic flowmeter
to integrate the flow velocities measured from different sound paths. Therefore, different weighted integration methods of the flow velocities on different sound paths, such as the
Gauss-Jacobi method [5] and the OWICS method [6], were investigated to obtain a robust and accurate estimation of mean flow velocity on a cross section of a pipe. Meanwhile, the optimal positions and weights of the acoustic paths were investigated by modeling the complete velocity field in a closed conduit by mathematic functions [7]–[10]. In addition, using computational fluid dynamics (CFD) simulation and getting the complete velocity distribution of rotating and
swirling turbulent flows, the effect of distorted flow profiles on ultrasonic flowmeter were also investigated [10]–[13].