20.500.12556/RUL-185908 Eksperimentalna analiza vpliva električnega polja na tokovno fokusiranje Experimental analysis of the influence of electric field on flow focusing Eksperimentalno smo ovrednotili vpliv električnega polja na kapljeviti mikro-curek, ki vertikalno izhaja iz plinsko dinamične virtualne šobe. Pri tem smo za kapljevine uporabili čisto in slano vodo, etilen glikol, izopropanol in etanol z volumskimi pretoki 0,1 – 4,0 ml/min, za plin pa zrak z volumskimi pretoki 10 – 80 l/h. Elektroda z napetostmi 2 – 8 kV je bila nameščeno 10 mm pod šobo. Analizirani so bili tokovni tipi (curljanje, kapljanje, opletane ter kombinacije med njimi) ter premer curkov. Za vse kombinacije procesnih parametrov smo izdelali diagrame tokovnih tipov, ki se precej razlikujejo za različne kapljevine. Meritve so pokazale, da električno polje pri pretokih zraka ~25 l/h stabilizira curek, pri pretokih ~65 l/h pa pospeši njegov razpad. Analiza curkov za etilen glikol s premeri med 132 in 430 µm je pokazala zoženje do 50 % pri napetosti ~6000 V in povečanje do 115 % pri napetosti ~2000 V pri čemer je zožanje izrazitejše na večji, povečanje pa na manjši oddaljenosti od šobe. Identificirani smo novo opažen tokovni tip, kjer se curek etanola pri napetosti ~8000 V, pretokih plina 0 – 40 l/h in kapljevine 1 – 3 ml/min spremeni v kapljevito ploskev. Izsledki raziskave so pomembni za dostavo vzorcev v serijski kristalografiji. We experimentally evaluated the influence of an electric field on a liquid micro-jet, emerging vertically from a gas dynamic virtual nozzle. The liquids used included purified water, saline solution, ethylene glycol, isopropanol and ethanol at liquid flow rates of 0.1 – 4.0 ml/min and air flow rates of 10 – 80 l/h. An electrode, operated at voltages 2 – 8 kV was positioned 10 mm bellow the nozzle. Flow types (dripping, jetting, whipping and their combinations) and jet diameters were analysed. For all process parameter combinations flow type diagrams were constructed and differed markedly between liquids. Measurements showed the electric field stabilising jets at gas flow rates ~25 l/h, whereas at flow rates ~65 l/h it accelerated jet breakup. Analysis of ethylene glycol jets with diameters between 132 – 430 µm demonstrated thinning to 50 % at ~6000 V and thickening to 115 % at ~2000V, with a thinning prevalent downstream and thickening closer to the nozzle. We identified a previously unreported flow type, in which an ethanol jet transformed into a liquid sheet at ~8000 V and at gas and liquid flow rates of 0 – 40 l/h and 1 – 3 ml/min, respectively. Research findings are important for sample delivery in serial crystallography. tokovno fokusiranje virtualna dinamična plinska šoba električno polje eksperiment diagram tokovnega tipa premer curka flow focusing gas dynamic virtual nozzle electric field experiment flow type diagram jet diameter true false false Slovenski jezik Angleški jezik Magistrsko delo/naloga 2026-08-22 08:32:05 2026-08-22 08:32:08 2026-08-23 04:09:54 0000-00-00 00:00:00 2026 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 1970-01-01 288199 48525.pdf 48525.pdf 1 635E1EDC0187C8A7607F1964ACE96758 73968b1c04321999dd4150cc07db0fd2444237512af1832ccaed581c6c1234c5 ce353db1-9df2-11f1-9b0d-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=244915 Fakulteta za strojništvo 0 0 0