抄録
Two ultrasound based methods for simultaneous characterizations of instantaneous velocity profiles of two-phase (liquid and gas) flow have been explored. Measurements of velocity profiles of both liquid phase and gas phase have been carried out for bubbly counter-current flow in a vertical pipe of 5cm pipe diameter (liquid flowing downwards and gas upwards). Two ultrasonic basic frequencies, 2MHz and 8MHz, are used independently and simultaneously along the sound path for measurement of bubble and liquid velocities respectively. The measurement methods are therefore referred to as the ultrasonic multiwave method. For signal processing, one method uses the ultrasonic Doppler method (UDM) and the other uses the ultrasonic time domain cross-correlation (UTDC) one. Based on the measured results, assessment of each method, when they are applied to this particular case of two-phase flow, is clarified.
