20.500.12556/RUL-185590 A computational investigation of microjet focusing with secondary fluid and compressible gas Double-flow focusing nozzles (DFFNs) are used to produce liquid microjets for sample delivery in serial femtosecond crystallography (SFX), where crystallized samples are dispersed in a primary liquid jet and delivered into the x-ray beam path. Such jets are generated by focusing a primary liquid jet with a coaxial secondary liquid and outer gas. Precise control of microjet stability and morphology is crucial for efficient sample delivery. This study presents a comprehensive numerical model of double-flow focused liquid jets from a DFFN, where the liquid phase consists of water and ethanol, and the focusing gas is helium. An axisymmetric, Newtonian, compressible, two-phase gas– liquid and two-component water–ethanol model is formulated and solved using the finite-volume method and volume-of-fluid framework. The water–ethanol mixing and resulting changes in density, viscosity, and surface tension as a function of ethanol concentration and tem perature are simulated using the Jouyban–Acree model. The jet characteristics as a function of material mixture properties, focusing-gas compressibility, and temperature are investigated numerically. A parametric analysis is performed over the typical SFX operating range, varying the water and ethanol flow rates from 0 to 20 ▫$\mu$▫l/min and the helium gas flow rate from 0 to 20mg/min. Jet stability, diameter, length, and velocity are analyzed. The influence of local mixture properties, mapped onto the Ca–We plane, reveals transitions between viscous-dominated and inertia-driven jetting regimes. The predicted jet diameters are consistent with the Young–Laplace equation and scal ing expression. The findings provide a physical insight required for the virtual design of DFFNs. serial crystallography double-flow-focusing jet-length serijska femtosekundna kristalografija fokusiranje z dvojnim tokom dolžina curka true false true Angleški jezik Slovenski jezik Članek v reviji 2026-08-11 13:14:53 2026-08-11 13:15:01 2026-08-12 04:03:49 0000-00-00 00:00:00 2026 0 0 15 str. iss. 8, art. 082003 Vol. 38 2026 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 532.57 1089-7666 doi.org/10.1063/5.0342127 287497987 Zahoor..._A_computational_investigation....pdf Zahoor..._A_computational_investigation....pdf 1 021562257F4EE84B8B279BD36F74496D 39333057ef1afa22ed41fef85a92a628cc364aa9fad9e03b09652ac6f53de727 df406abc-9575-11f1-9b0d-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=244267 https://pubs.aip.org/aip/pof/article/38/8/082003/3400529/A-computational-investigation-of-microjet-focusing 1 8be827d2-9575-11f1-9b0d-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=244266 Fakulteta za strojništvo 0 0 0