Eksperimentalna analiza nesimetričnih šob za doseganje podmikronskih curkov in kapljic

Savšek, Gal (author), Šarler, Božidar (mentor)

V magistrski nalogi je bila zasnovana, eksperimentalno preizkušena in ovrednotena nesimetrična hipodermična GDVN (HDN) za proizvodnjo mikro curkov in kapljic za dostavo vzorcev pri serijski femtosekundni kristalografiji (SFX) in vizualizaciji posameznih delcev (SPI). Za preizkušanje premera, dolžine in hitrosti curka ter kapljic je bila postavljena eksperimentalna proga, s katero smo zajemali videoposnetke, jih analizirali na podlagi računalniškega vida ter merili tlačne padce plina skozi šobo in volumske pretoke kapljevine. Za usmerjevalni plin vodnega curka smo uporabili dušik. Izvedli smo parametrično eksperimentalno študijo vpliva pretoka kapljevine, tlačnega padca plina ter premera grla šobe na premer in dolžino curka ter velikost kapljic. Opravili smo osemnajst meritev v območju We plina 200-25000, We kapljevine 3-65, Re plina 2600-18000 in Re kapljevine 9-65. Izmerjeni curki so bili premera 0,46-2,02 µm in dolžine 9-96 µm. Premeri kapljic so bili 0,75-0,95 µm. Ugotovljeno je bilo, da HDN proizvajajo stabilne curke in kapljice podmikronskih premerov pri volumskih pretokih kapljevine 0,6-1,0 µl/min. Ugotovili smo: (I) da so HDN primerne za SFX glede na debelino in ocenjeno hitrost (približno 100 m/s) curka, ne pa tudi glede na dolžino curka, (II) da so HDN primerne za SPI, ker proizvajajo majhne kapljice, ki jih ni možno doseči s klasičnimi GDVN.

• Language: Slovenian
• Keywords: nesimetrična šoba, mikro-curek, tokovno usmerjanje, eksperiment, video analiza
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: FS - Faculty of Mechanical Engineering
• Place of publishing: Ljubljana
• Publisher: [G. Savšek]
• Year: 2023
• Number of pages: XX, 58 str.
• PID: 20.500.12556/RUL-152381
• UDC: 004.942:519.876.5(043.2)
• COBISS.SI-ID: 183138819
• Publication date in RUL: 23.11.2023

Secondary language

• Language: English
• Title: Experimental analysis of asymmetric nozzles for achieving submicron jets and droplets

Abstract

In this Master thesis, an asymmetric hypodermic GDVN (HDN) was designed, experimentally tested and evaluated for the purpose of producing micro-jets and droplets for sample delivery in serial femtosecond crystallography (SFX) and single particle imaging (SPI). An experimental set-up was built to evaluate the diameter, length and velocity of the jet and droplets. It was designed to capture and analyse footage using computer vision, measure gas pressure drops and liquid volume flow rates. Nitrogen was used as a flow focusing gas for the water jet. A parametric experimental study was carried out to investigate the influence of liquid flow rate, gas pressure drop and nozzle orifice diameter on the jet diameter, jet length and droplet size. Eighteen measurements were performed in the range of gas We 200-25000, liquid We 3-65, gas Re 2600-18000 and liquid Re 9-65. The diameter of jets ranged 0,46-2,02 μm and the length of jets ranged 9-96 μm. The diameter of droplets ranged 0,75-0,95 μm. HDNs were observed to produce stable jets and droplets of sub-micron diameters at volume flow rates of 0,6-1,0 μl/min. The conclusions were (I) that HDNs are suitable for SFX with respect to the jet diameter and estimated velocity (approximately 100 m/s), but not with respect to the jet length, (II) that HDNs are suitable for SPI as they produce small droplets that cannot be produced by conventional GDVNs.

• Keywords: asymmetric nozzle, micro-jet, flow focusing, experiment, video analysis