A CFD simulation for the ultrasonic flow meter with a header

Abstract

Ultrasonic flow meter has been used in natural gas metering for many years, however, the measurement accuracy of the ultrasonic flow meter is affected by the header, which leads to non-perfect fluid state in the flow meter. The objective of this research is to discuss the issues of dual-path ultrasonic flowmeter with a header. Computer fluid dynamic (CFD) method is used to simulate standard turbulent model. It is found that the flow state in the downstream is distorted by the header with secondary turbulence, swirl etc., and the velocity distribution of the gas is asymmetric; the farther the distance between the ultrasonic flow meter and the header, the smaller the distortion and the simulation error. When the downstream straight pipe length is greater than 27 − D (Diameter), the flow state will be steady. With the same diameter of the header, the shorter the meter header the greater the distortion of the gas in the downstream pipe. With the same length of the header, the smaller the diameter, the greater the distortion of the gas in the downstream. These results have a great guiding significance in the optimal design of the flow meter installation structure.

Keywords

• Pipe manifold
• Ultrasonic flow meter
• Measurement performance
• Indication error