Transmission-mode ultrasonic measurement for gas bubble detection

Non-invasive ultrasonic tomography is a practical solution of extracting cross-section information regarding the process of two-phase flow. For gas/water two-phase flow, the ultrasonic energy would be reflected about 99.94% at the gas/water interface due to the great differences between the acoustic impedance of water and gas. In this paper, the relations between pressure or voltage loss and bubble diameter has been studied by simulation results and experimental results, respectively by the ultrasonic transmission method. Both results showed that the transmission-mode measurement method has good resolution on the bubble diameter.