Bernoulli excitation and detection of gas bubbles

✍ Scribed by R.H. Telling; Alan J. Walton

• Book ID: 104263432
• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 188 KB
• Volume: 39
• Category: Article
• ISSN: 0041-624X
• DOI: 10.1016/s0041-624x(01)00075-0

✦ Synopsis

A simple method is proposed for detecting and sizing bubbles in pipeline ¯uid ¯ow. This is based on changing the pressure of the ¯uid, which in turn excites volume oscillations in the bubble. If the change in pressure is of sucient brevity and magnitude, the transient distortion results in excitation of the bubble into radiative oscillation at its natural frequency. In a moving ¯uid, the Bernoulli equation predicts that such a pressure change can be achieved through a suitable gradient in the ¯ow velocity. In the experiments described here, this is achieved by altering the cross-sectional area of the pipe in which the ¯uid is ¯owing. We demonstrate the ecacy of this excitation method and, by detecting the radiated sound using a nearby hydrophone, determine the size of individual bubbles from their characteristic oscillation frequency.