dc.contributor	Sedlář Milan, RNDr. CSc. : 65631
dc.contributor.advisor	Müller Miloš, Ing. Ph.D. : 55450
dc.contributor.author	Duran, Myka Mae Campo
dc.date.accessioned	2019-10-14T10:25:36Z
dc.date.available	2019-10-14T10:25:36Z
dc.date.committed	2020-4-30
dc.date.defense	2019-05-29
dc.date.submitted	2018-11-1
dc.date.updated	2019-5-29
dc.degree.level	Ing.
dc.description.abstract	The assessment of aggressiveness of cavitation phenomena through direct measurement of impact forces produced by bubble collapse is studied. This was done by recording impact forces from a commercially available Polyvinylidene Fluoride (PVDF) film sensor which is exposed to cavitation generated by ultrasonic transducer equipment. The ideal number of runs which will better represent the cavitation phenomena was first identified. Results showed good repeatability of every run and that a minimum of 3 experimental trials with time duration of 15 ms are enough to get a consistent data. The preparation of the PVDF films was optimized by selecting among four PVDF films that were setup differently, namely, a PVDF film as obtained from the supplier, a PVDF film topped with one layer of tape as an added protection, PVDF film with two layers of protective tape, and lastly a PVDF film which is folded into half. The PVDF film with one layer of tape is found to be the most suitable film for aggressiveness tests in terms of sensitivity and durability from cavitation damage. This film was then subjected to three different vibration amplitudes and it showed that increasing the oscillation amplitude leads to stronger impacts. Although most impacts were seen to occur at each horn vibration period, there were prominent high impact forces observed to arise after some cycles of horn vibration. This suggests that bubbles coagulate to form large cavity and then collapse more violently at a frequency lower than the frequency of ultrasonic horn vibration. Moreover, these strong impacts occur at a frequency that decreases as the vibration amplitude is increased. The obtained impact force signal was then compared to a previously obtained pitting test data which utilized the same experimental setup as used in this study. A remarkably high difference in the order of magnitude was seen between the cumulative peak rate and pit rate indicating that not all impacts cause pits on the surface of the material. Additionally, if it is assumed that a pit is formed from a single impact force during the incubation period, then a load of 319 N is necessary to create a 0.9 m diameter pit on aluminum alloy.	en
dc.description.mark
dc.format	75
dc.format.extent	Ilustrace, Grafy, Tabulky None
dc.identifier.signature	V 201901434
dc.identifier.uri	https://dspace.tul.cz/handle/15240/153981
dc.language.iso	an
dc.relation.isbasedon	matsymblbrack1matsymbrbrack KIM, Ki-Han, Georges CHAHINE, Jean-Pierre FRANC a Ayat KARIMI. Advanced experimental and numerical techniques for cavitation erosion prediction. Dordrecht: Springer, [2014]. Fluid mechanics and its applications, v. 106.
dc.relation.isbasedon	vsp5mm matsymblbrack2matsymbrbrack Acoustic cavitation and bubble dynamics. New York, NY: Springer Berlin Heidelberg, 2017. ISBN 9783319682365.
dc.relation.isbasedon	vsp5mm matsymblbrack3matsymbrbrack BRENNEN, Christopher E. Cavitation and bubble dynamics. New York: Oxford University Press, 1995. ISBN 0195094093.
dc.relation.isbasedon	vsp5mm matsymblbrack4matsymbrbrack FRANC, Jean-Pierre a Jean-Marie MICHEL. Fundamentals of cavitation. Boston: Kluwer Academic Publishers, c2004. ISBN 1402022328.
dc.rights	Vysokoškolská závěrečná práce je autorské dílo chráněné dle zákona č. 121/2000 Sb., autorský zákon, ve znění pozdějších předpisů. Je možné pořizovat z něj na své náklady a pro svoji osobní potřebu výpisy, opisy a rozmnoženiny. Jeho využití musí být v souladu s autorským zákonem https://www.mkcr.cz/assets/autorske-pravo/01-3982006.pdf a citační etikou https://knihovna.tul.cz/document/26	cs
dc.rights	A university thesis is a work protected by the Copyright Act. Extracts, copies and transcripts of the thesis are allowed for personal use only and at one?s own expense. The use of thesis should be in compliance with the Copyright Act. https://www.mkcr.cz/assets/autorske-pravo/01-3982006.pdf and the citation ethics https://knihovna.tul.cz/document/26	en
dc.rights.uri	https://knihovna.tul.cz/document/26
dc.rights.uri	https://www.mkcr.cz/assets/autorske-pravo/01-3982006.pdf
dc.subject	Cavitation	cs
dc.subject	ultrasonic cavitation	cs
dc.subject	PVDF Sensor	cs
dc.subject	Cavitation	en
dc.subject	ultrasonic cavitation	en
dc.subject	PVDF Sensor	en
dc.title	Investigation of the Cavitation Aggressiveness Using PVDF Sensors	cs
dc.title	Investigation of the Cavitation Aggressiveness Using PVDF Sensors	en
dc.type	diplomová práce	cs
local.degree.abbreviation	Navazující
local.degree.discipline	KSA
local.degree.programme	Mechanical Engineering
local.degree.programmeabbreviation	N2301
local.department.abbreviation	KEZ
local.faculty	Fakulta strojní	cs
local.faculty.abbreviation	FS
local.identifier.author	S17000401
local.identifier.stag	39425
local.identifier.verbis	kpw06584670
local.note.administrators	automat
local.poradovecislo	1434

Investigation of the Cavitation Aggressiveness Using PVDF Sensors

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