Use of gas bubbles for ultrasound Doppler flow velocity profile measurement

摘要

Ultrasonic velocimetry based on the Doppler shift effect accurately provides quasi-instantaneous flow fields for fluids with a sufficiently high acoustic scattering level. However, ultrasonic velocity instruments are known to perform poorly in clear water with low acoustic scattering level, which are frequent conditions in laboratory applications. This work confirms a technique to solve the problem by seeding the flow with micro hydrogen bubbles, generated by means of electrolysis.