An FEM Analysis of Ultrasonic Transmission to Detect the Liquid-Liquid Interface in Containers with Regular Shapes

This research explores the detection of the interface height between two liquids in storage containers using ultra-sonic transducers in through-transmission mode. Using FEM simulations, the study analyzes ultrasonic transmission through oil/water interfaces in both rectangular and cylindrical containers. The approach involves 2D FEM modeling to simulate interface detection with broadband ultrasonic pulses in the time domain. A FE model was developed to accommodate both types of containers. The model includes two liquid phases (oil and water) separated by an interface. Experiments were carried out using two transducers attached at the same horizontal level on opposite walls of the containers. In rectangular containers, the transducers are positioned parallel to the interface, while in cylindrical containers, their angles vary along the curved wall to optimize signal reception. Following data acquisition, the research analyzed the data to determine the levels of the liquid. The findings reveal that the maximum amplitude in the transmitted wave occurs when it aligns with the separation layer at a 10-degree angle. The study concludes that measuring maximum amplitude is an effective way to determine liquid levels, accelerating the process of identifying the position of the separation layer.