CFD simulation and experimental study of ultrasonic flowmeters

This paper deals with CFD simulation and experimental study of ultrasonic flowmeters. A mathematical model of an ultrasonic flowmeter (USM) was built for studying the errors of flow measurement in disturbed flows. The method of defining the position coordinates of the acoustic paths and their weighting factors was improved based on the Gauss-Jacobi method of integration (i.e. the weighting function was improved) which provided the possibility to raise the accuracy of the turbulent flow velocity integration. The effectiveness of the improved method was verified using the Salami functions. New methodology for improving the mathematical model of USM is proposed. According to this methodology the dependence of the calibration factor on the Reynolds number is introduced into the model. A technique for studying the errors of USM in disturbed flows was developed on the basis of the proposed methodology. The developed technique was verified by comparing the CFD simulation results for a 3D model of an acting USM with the experimental results for this meter obtained by means of a reference test rig. The deviation of the simulation results from the obtained experimental data is not more than 1 %. Recommendations on defining the pipe straight lengths for the double-path chordal flowmeters were developed on the basis of the investigation results.