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doctoral thesis
Vrednovanje točkastog izvora ultrazvuka u linearnom i nelinearnom načinu rada
Zagreb: University of Zagreb, Faculty of Electrical Engineering and Computing, 2008. urn:nbn:hr:168:776223
Petošić, Antonio
University of Zagreb
Faculty of Electrical Engineering and Computing
Department of Electroacoustics

Institutional repository: FER Repository

Cite this document

Petošić, A. (2008). Vrednovanje točkastog izvora ultrazvuka u linearnom i nelinearnom načinu rada (Doctoral thesis). Zagreb: University of Zagreb, Faculty of Electrical Engineering and Computing. Retrieved from https://urn.nsk.hr/urn:nbn:hr:168:776223

Petošić, Antonio. "Vrednovanje točkastog izvora ultrazvuka u linearnom i nelinearnom načinu rada." Doctoral thesis, University of Zagreb, Faculty of Electrical Engineering and Computing, 2008. https://urn.nsk.hr/urn:nbn:hr:168:776223

Petošić, Antonio. "Vrednovanje točkastog izvora ultrazvuka u linearnom i nelinearnom načinu rada." Doctoral thesis, University of Zagreb, Faculty of Electrical Engineering and Computing, 2008. https://urn.nsk.hr/urn:nbn:hr:168:776223

Petošić, A. (2008). 'Vrednovanje točkastog izvora ultrazvuka u linearnom i nelinearnom načinu rada', Doctoral thesis, University of Zagreb, Faculty of Electrical Engineering and Computing, accessed 24 December 2024, https://urn.nsk.hr/urn:nbn:hr:168:776223

Petošić A. Vrednovanje točkastog izvora ultrazvuka u linearnom i nelinearnom načinu rada [Doctoral thesis]. Zagreb: University of Zagreb, Faculty of Electrical Engineering and Computing; 2008 [cited 2024 December 24] Available at: https://urn.nsk.hr/urn:nbn:hr:168:776223

A. Petošić, "Vrednovanje točkastog izvora ultrazvuka u linearnom i nelinearnom načinu rada", Doctoral thesis, University of Zagreb, Faculty of Electrical Engineering and Computing, Zagreb, 2008. Available at: https://urn.nsk.hr/urn:nbn:hr:168:776223

Metadata
TitleVrednovanje točkastog izvora ultrazvuka u linearnom i nelinearnom načinu rada
Title (english)Evaluating ultrasound point source in the linear and nonlinear operating mode
AuthorAntonio Petošić
MentorBojan Ivančević (mentor)
Committee memberHrvoje Domitrović (član povjerenstva)
Committee memberBojan Ivančević (član povjerenstva)
Committee memberIgor Zorić (član povjerenstva)
Committee memberStanko Tonković (član povjerenstva)
Committee memberMarijan Klarica (član povjerenstva)
GranterUniversity of Zagreb
Faculty of Electrical Engineering and Computing
(Department of Electroacoustics)
Zagreb
Defense date and country2008, Croatia
Scientific / art field,
discipline and subdiscipline		TECHNICAL SCIENCES
Electrical Engineering
Electronics
Universal decimal classification
(UDC)		621.3 - Electrical engineering
53 - Physics
Abstract
Tijekom višegodišnjeg razvoja niskofrekvencijskih ultrazvučnih uređaja za primjene u neurokirurškim operacijama ostali su problemi točnog definiranja njihove akustičke snage i intenziteta.U radu su predložene i analizirane tri metode za određivanje akustičke snage točkastog izvora ultrazvuka. Prva metoda temelji se na mjerenju prostorne raspodjele magnitude dinamičkog tlaka u slobodnom akustičkom polju i proračunu isijane akustičke snage pri linearnom i nelinearnom načinu rada ultrazvučnog izvora. Drugi način vrednovanja točkastog izvora ultrazvuka temeljen je na određivanju nadomjesnih parametara ekvivalentnog elektromehaničkog titrajnog kruga koji opisuje gibanje vrha sonotrode izvora u okolini serijske rezonantne frekvencije longitudinalnog moda titranja. Parametri nadomjesnog kruga određeni su u okolini serijske rezonantne frekvencije i izračunat je koeficijent elektroakustičkog iskorištenja. Treća metoda je mjerenje izlazne akustičke snage ultrazvučnog izvora pomoću kalorimetrijske metode. Iz promjene unutrašnje temperature kalorimetrijskog sustava računaju se gubici sustava i odgovarajuća izlazna akustička snaga točkastog izvora ultrazvuka. Iz priloženih rezultata zaključeno je da se rezultati vrednovanja elektromehaničkog dijela UZ izvora mogu usporediti s rezultatima mjerenja isijane akustičke snage u slobodnom akustičkom polju u linearnom načinu rada. Kalorimetrijska metoda pokazala se kao najopćenitija jer u sebi obuhvaća i akustičku i toplinsku energiju koja se oslobađa tijekom procesa kavitacije.
Abstract (english)
During interdisciplinary collaboration in scientific-research programmes in the field of power ultrasound several types of ultrasound point sources have been developed. The main problem left behind was how to measure acoustic power of the source. Three different methods for measurement of acoustic power have been considered during this work. First method is measurement of delivered acoustic power in the free acoustic field. The pressure field of the transmitter has been measured with calibrated hydrophone system at different electrical power excitation levels. The second considered method for measuring acoustic power was evaluating electromechanical part of ultrasound transmitter. The input electrical impedance of unloaded and loaded ultrasound transmitter have been measured at different voltage excitation levels. The parameters of equivalent circuit have been determinated on resonance frequency and electroacoustic efficiency factor is calculated using RLC equivalent circuit approach. Third method for measuring output acoustic power is calorimetric method. Measuring the delivered acoustic power in the free acoustic field, only acoustic power contribution is included in results. During cavitation, collapsing bubbles in front of sonotrode tip are secondary sound sources but they also generate heat energy which can't be measured using hydroacoustic measurement system so the calorimetric method is used. It has been shown that during cavitation, the majority of energy released is heat and not acoustic energy.
Keywords
Keywords (english)
Languagecroatian
URN:NBNurn:nbn:hr:168:776223
Study programmeTitle: Doctoral study programme "Electrical Engineering and Computing"
Study programme type: university
Study level: postgraduate
Academic / professional title: doktor/doktorica znanosti, po-dručje tehničkih znanosti (doktor/doktorica znanosti, po-dručje tehničkih znanosti)
Type of resourceText
File originBorn digital
Access conditionsClosed access
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Created on2020-05-28 11:32:37