Transmission Type Ultrasonic Imaging of Horizontal Two-Phase Flow

Abstract

Ultrasonic technique was widely applied for the measurement of two-phase flow, however, the majority techniques deal primary with pulse echo technique under higher operating sound frequency in a MHz order since higher accuracy can be obtain for the dynamic gas-liquid interface locations. On the other hand the transmission type ultrasonic methods was also developed for bubbly flow diagnostics for the time and cross sectional averaged void fraction measurement or bubble two-phase flow parameter determination by pulse echo techniques with higher operating sound frequency in a MHz order. In this work, the transmission type ultrasonic imaging of horizontal two-phase flow was experimentally investigated. Ultrasonic transducer used is 150 kHz and time averaged void fraction results for stratified flow was compared with capacitance void measurement and ultrasonic pulsed echo techniques. The results show that the transmission intensity for the stratified flow pattern decreases with increasing void fraction until 55% of void then increases with increasing void fraction till 100%. An application to plug, slug and annular flow regime also investigated in detail.