Laserski preboj v vodi pri nizkih tlakih

Mehle, Andraž (author), Agrež, Vid (mentor)

V primerjavi z mehurčki pri normalnem in višjem tlaku dinamika mehurčka v podtlaku ni najbolj podrobno raziskana. Zato je v tej nalogi predstavljen postopek zasnove in konstrukcije tlačne komore, ki omogoča doseganje nizkih tlakov, ter analiza lasersko induciranih mehurčkov, generiranih v tem okolju. V prvem delu naloge je opisano teoretično ozadje lasersko induciranega mehurčka, drugi del pa se osredotoča na opis dizajniranja tlačne komore. Zasnovali smo jo znotraj dimenzij, ki omogočajo prileganje na pozicionirno mizico, nato pa preverili trdnost s simuliranjem obremenitve v programu SolidWorks. 3D natiskano komoro smo testirali in našli pomanjkljivosti, kot sta neustrezno tesnjenje in vsrkavanje vode iz komore, popravke pa integrirali v kasnejše verzije. Ko je komora ustrezala pogojem, smo z laserjem generirali mehurčke v vodi pri štirih različnih tlakih in jih posneli s hitro kamero. V tretjem delu naloge smo slike analizirali in primerjali s teoretičnimi vrednostmi premerov sferičnih mehurčkov. Raziskava je razkrila razlike v velikosti in času obstoja pri mehurčkih, generiranih pri normalnem in nizkem tlaku. Pridobljeno znanje deluje kot podlaga za nadaljnja raziskovalna dela, ki bi preiskovala vplive okolja na kavitacijske mehurčke ali učinek kolapsa mehurčkov v podtlačnem okolju na njegovo okolico.

• Language: Slovenian
• Keywords: laserski preboj, kavitacija, mehurček, nizki tlaki, tlačna komora
• Work type: Final paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: FS - Faculty of Mechanical Engineering
• Place of publishing: Ljubljana
• Publisher: [A. Mehle]
• Year: 2024
• Number of pages: XII, 29 str.
• PID: 20.500.12556/RUL-155763
• UDC: 621.375.826:532.528:004.414.23(043.2)
• COBISS.SI-ID: 193709315
• Publication date in RUL: 17.04.2024

MEHLE, Andraž, 2024, Laserski preboj v vodi pri nizkih tlakih [online]. Bachelor’s thesis. Ljubljana : A. Mehle. [Accessed 14 April 2025]. Retrieved from: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=eng&id=155763

Secondary language

• Language: English
• Title: Laser induced breakdown in water at low pressures

Abstract

In comparison to cavitation bubbles ocurring under normal or higher pressure, the bubble dynamics in negative pressure have not been researched in detail. This is the reason why this thesis contains description of design and construction of a pressure chamber that will enable low pressures and analysis of laser-induced cavitation bubbles. The first part of the thesis covers the theoretical background of a laser-induced bubble, while the second part focuses on the design of a pressure chamber. We designed it within dimensions that enable it to fit on positioning equipment and after, we checked it's integrity via solidworks simulation. The 3D printed chamber was tested for flaws, such as inadequate sealing and water sucking. We integrated their corrections in later versions and after the chamber met the standards, we generated laser-induced cavitation bubbles at four different pressures and captured images of the bubbles. In the third part of the thesis, we analyzed and compared theoretical data of the bubble's diameter with actual diameters. Our research has shown the differences in the size and time of existence, between bubbles generated in atmospheric and negative pressures. Gathered research works well as a foundation for future work that would focus on the effects of the surroundings on cavitation bubbles or the effect these bubbles' collapse would have on their surroundings if they were generated in negative pressures.

• Keywords: laser breakdown, cavitation, bubble, low pressures, pressure chamber