Liquid-Liquid Interface Localization Using Wave Pattern Measured by Ultrasonic Through-Transmission Mode

This study investigates the interference patterns and diffraction effects of acoustic waves at the interface between two immiscible liquids, focusing on the ultrasonic pitch-catch technique. Research examines wave patterns at a water-oil interface, employing through-transmission mode to locate the interface. An experimental setup was created with transducers immersed in a tank containing water and oil, separated by a clear interface. Experiments were conducted by analyzing the relative position of the interface with respect to the transducer's acoustic axis. The amplitude of the received signal shows a local minimum due to destructive interference and a maximum variation in time-of-flight due to differing propagation speeds. The resulting wave-amplitude pattern was processed by analyzing it with the vertically displaced pattern. The through-transmission mode was utilized to locate the interface, which improved the understanding of ultrasound techniques to characterize multiphase systems.