Determination of the acoustic nonlinearity parameter B/A using a phase locked ultrasonic interferometer

Jevon R. Davies, Jonathan Tapson, Bruce J. P. Mortimer
1998 Journal of the Acoustical Society of America  
me acoustic nonlinearity parameter WA is important for charac[erising amustic propagation in fluids. Rat &velopments in the fields of shockwaves and biomedid ultrasonics have necessitated an amurate method for measuring this quantity.~s paper presents a new technique based on an ultrasonic hterferometer that atlows awurate measurements of the change in sound speed within a liquid mvity. The system makes use of a novel mntinuous wave phase lmhg principle, which has the effwt of nulfiffig many of
more » ... f nulfiffig many of tie non-ltitities inherent in the amustic interferometer. me phase-link circui~automati~y adjusts the frequency so as to kq an ewct integer number of waves in the mvity regardless of changes in sound e. k this way, B/A is determined by relating a small change in ambient pressure (less b 2 bar) to a change in frequency under isenbopic conditions. B/A vsdues are dcutated using this e~rimentat setup for several liquids including two slow sound speed fluombon liquids FC43 and FC-75. TRODUCTION
doi:10.1121/1.422901 fatcat:r6rtxvowdfbcrddedsz5pxukzi