Influences of Liquid Temperature on Flow Rate Measurements using Guided Waves Generated from Ring Transducers

Abstract

Micro flow rate measurements are required for manufacturing and medical fields. Straight type ultrasonic flowmeter can measure the liquid flow by using guided waves. However, guided waves propagate by vibrating intricately along boundaries, so it is difficult to reveal their characteristics. In addition, the time difference between two receiving waves across two transducers differs depending on the temperature of the liquid, which can cause errors in flow rate measurements. In this paper, the theoretical analysis method for guided wave flowmeter is introduced to investigate the influence of water temperature on flow rate measurement. The simulated time difference is calculated by using this method, while the experimental time difference is obtained in a circulation system. By comparing simulated and experimental values, this theoretical analysis can be confirmed to be valid for revealing the temperature dependence.