Numerical and experimental studies on the influences of flow field on the measurement accuracy of ultrasonic water meters

Abstract

CFD modelling and experiments are carried out to study the influences of flow field on the measurement accuracy of ultrasonic water meters. The swirl generator and flow disturber are selected to change the flow field distributions inside the pipe. The calculation results show that the installation of left-handed swirl generator induces a specific flow pattern of the fluid inside the pipe, while the installation of flow disturber leads to the distortion of the axial velocity distributions. The critical distance of the fluid reaching the steady flow is 10D for left-handed swirl generator and flow disturber. In the experiment part, six different ultrasonic water meters are selected for the intrinsic errors tests. The results show that the installations of swirl generator and flow disturber induce the intrinsic errors shift to negative values. Compared with the flow disturber, the swirl generator has greater impact on the measurement accuracy.

Keywords

• Flow field
• Disturbance generators
• Ultrasonic water meters
• CFD