Research on coupling method of flow field and acoustic field based on COMSOL for ultrasonic flowmeter

Ultrasonic flowmeter is widely used in industry. As a high precision measuring instrument, its accuracy is affected by the acoustic field and flow field distributed in pipe. In order to study the coupling mechanism of both fields, a simulation analysis method based on COMSOL Multiphysics simulation software is established. Firstly, the real flow field is obtained by the Computational Fluid Dynamics (CFD) module, which can be directly coupled to the acoustic module. Secondly, under the background flow fields, the ray acoustics and aerodynamic acoustics modules are analyzed respectively for proper settings, in which the effects of sound source and boundary conditions on simulation results are mainly discussed. Based on the proposed method, acoustic ray propagation trajectory, measurement error and sound pressure distribution on receiving transducer are studied. Finally, the simulation results have been compared to experiment.