Naslov
Electro-Mechanical and Acoustic Characterization of Low-Frequency Ultrasound Devices

Autori
Antonio Petošić, Mateja Babić, Ivan Đurek, Bojan Ivančević

Vrsta, podvrsta i kategorija rada
Radovi u zbornicima skupova, cjeloviti rad (in extenso), znanstveni

Izvornik
6th Congress of Alps-Adria Acoustics Assosiation 16.-17. October 2014 Graz, Austria / Frantz Graf - Graz : Austrian Acoustics Society, 2014, 1-9

ISBN
978-3-200-03921-6

Skup
6th Congress of Alps-Adria Acoustics Assosiation

Mjesto i datum
Graz, Austrija, 16.10.2014. - 17.10.2014

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Low-frequency ultrasound device ; electromechanical characterization ; the input electrical impedance in the linear and nonlinear operating mode ; cavitation activity ; radiation acoustic impedance ; loading medium viscosity ; acoustic streaming and turbulence

Sažetak
The ultrasound transducer for microsurgery operations working at 25kHz in the longitudinal operating mode have been developed with three different removable sonotrode tips. The radiated acoustic power of the device driven at different excitation levels has been determinated experimentally by using two different measurement methods suggested by International standards IEC 61847 and IEC 61088. The first method considered in research for determination of the efficiency of transducer is electromechanical characterization. The measurements of the input electrical impedance have been done in unloaded and loaded conditions, in mediums with diffferent viscosities, at different excitation levels by using constant voltage magnitude frequency sweeping signal. The governing nonlinear 1-D differential equation describing the transducer behaviour at different excitation levels is determinated with included loading acoustic impedance in front of the sonotrode tip at different working conditions. It is observed that the input electrical impedance of the device is significantly changed depending on the tip position in complex standing wave field in the vessel. When linear acoustic principles are used, the loading radiation impedance in front of the tips should be decreased due to decrease of effective loading medium density and sound speed velocity. In this research it is observed that the input electrical impedance of the device is increased when cavitation activity is present in front of the sonotrode tips. The increase of the input electrical impedance is studied with respect to the medium turbulence and viscosity. The second method for determination of the acoustic power considered in this research is the calorimetric method. The dissipated acoustic power in restricted liquid volume is determinated at different excitation levels. The temperature increase of vibrating tranducer parts, the applied electrical power and the output acoustic intensity are determinated at several different excitation levels. The third method for determiation of acoustic power is measurement presusre distribution of the device in the anechoic pool. All measurement results are compared and discussed.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Elektrotehnika

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