OS9-5 Trial Measurement on Two-phase Flow using a Multi-wave Ultrasonic Velocity Profile Method : 3rd Report: Measurement of Slug Flow and Visualization using High-speed Camera

A new measurement technique referred to as multi-wave ultrasonic method was applied to measuring slug flow. The technique was developed for measuring two-phase flow using two different ultrasonic frequencies. The technique employs a multi-wave ultrasonic transducer (TDX) which includes two different ultrasonic elements. With emitting two kinds of ultrasonic at the same time, two kinds of ultrasonic echo signals can be obtained. The echo intensity reflected from liquid-gas interface is higher than that from micro particles seeded in water. Comparing with the each signal, echo signals from liquid-gas interface and micro-particles can be divided. Applying an ultrasonic time-domain cross-correlation method for the signals, velocity distributions of the both phases can be obtained at the same time and the position. Comparing the velocity data with the obtained images by using high-speed camera, it was confirmed that the multi-wave method can measure the both liquid and gas velocity distributions at the slug flow.