Computational Fluid Dynamics Numerical Simulation of an Ultrasonic Velocimeter

An ultrasonic velocimeter is a device with ultrasonic transmitter-receiver to detect the time between transmission and reception of ultrasonic waves and to calculate the velocity of fluid flow. The current domestic studies mainly focus on how to eliminate the measurement errors, but spare little attention to the influence of the model structure on the measuring wind field. In order to investigate the accuracy of a model velocimeter, the impact of the model structure on the wind velocity in the measuring wind field was addressed, the computational fluid dynamics (CFD) method was used to simulate the flow fields of different incoming flows from low speed to high, and to calculate the velocity profiles in the central area of the velocimeter and the average velocities in different cross sections. Consequently, the interference effect of the model velocimeter structure on the velocity in the central area of measurement was evaluated. The research results show that the velocities measured on the plane at the tops of measuring balls are the most accurate in spite of low or high incoming flow velocities. Therefore, the CFD method is proved to be a powerful tool for the model design of high-accuracy velocimeters.