Simulation and Modelling of Sound Field of Gas Ultrasonic Flowmeter by Gaussian Beam Method

Gas ultrasonic flowmeters are widely used in natural gas industry. In order to simulate and model the sound field at different flow velocities of gas ultrasonic flowmeter, the Gaussian beam method is firstly applied in this paper, which has high computational efficiency and wide range of applications compared with traditional ray acoustics. First, sound trajectories are traced with a certain angle by ray-tracing equation and Runge-Kutta algorithm. Besides, the fastest-ray model is firstly proposed and applied to reduce the measurement error up to 1.38%. Second, the characteristic parameters of traditional Gaussian beam method are recalculated according to flow velocity in pipe, thus a new formula of Gaussian beam method is obtained for gas ultrasonic flowmeter. Therefore, the whole sound pressure field is superimposed by all Gaussian beams. Compared with the Doppler solution, the applicability of the modified Gaussian beam method is verified. Finally, based on the proposed Gaussian beam method, sound pressure field is modelled and analyzed under both ideal uniform and fully developed turbulent flow profiles for gas ultrasonic flowmeter.