Optimization design and research of ultrasonic flowmeter based on time difference method

This paper presents an optimized design method for an ultrasonic flow meter (USFM) used in the semiconductor manufacturing field for liquid flow measurement. Based on fluid simulation, the impact of different inlet tube section angles on the velocity distribution within the measuring tube section of the USFM was analyzed, and a suitable inlet tube section angle of 45° was determined. Based on the average flow velocity on the acoustic channel line and the average flow velocity in the measuring tube section, a velocity correction factor was calculated to adjust the measured flow velocity to the actual flow velocity of the tested fluid. The USFM prototype was calibrated for flow rate and a compensation factor obtained to correct measured flow rate. The accuracy of the USFM was tested and found to reach 1.5 level, meeting the needs for liquid flow measurement in the semiconductor manufacturing field.