Demonstration of Non-Uniformity of Velocity Profiles Using 2D PIV

Abstract

This paper deals with the demonstration of the non-uniformity of velocity profiles in a DN 200 air circular pipe as part of the development of a newly designed tomographic ultrasonic flowmeter. The flowmeter should measure the flow quality independently. Therefore, different aerodynamic conditions were created by placing mechanical obstacles at the entrance of the measuring chamber, and these conditions were experimentally verified. As an experimental channel substituting a section with ultrasonic sensors, a glass segment was placed at the inlet of a suction pipeline, in front of which perforated plates were inserted to break the uniformity of the velocity profile. The two-dimensional Particle Image Velocimetry (2D PIV) method was used to measure in a plane lying in the longitudinal axis of the channel. The experimental setup and PIV system parameters are described. The results are presented as velocity profiles and contour diagrams in cross-sections at different longitudinal positions in the channel. The results show that the requirement of non-uniformity is satisfied. The used disturbing plates disturb the axial symmetry of the profiles and create a backflow.