Simulation of non-Newtonian gas-focused micro-jets in chocked gas flow regime

Zahoor, Rizwan (author), Bajt, Saša (author), Šarler, Božidar (author)

Stable liquid jets are crucial for successful serial crystallography experiments. They are produced from gas dynamic virtual nozzles (GDVNs), where the liquid from an inner capillary is focused by a co-flowing gas from an outer converging capillary. Our previously investigated non-Newtonian jets with incompressible and compressible focusing gas under atmospheric conditions were extended towards compressible chocked gas under vacuum conditions. An axisymmetric GDVN was considered with a fixed gas flow rate of 15 mg/min and liquid flow rate of 40 µl/min. A mixture formulation of the laminar compressible multiphase problem was solved within finite volume method and volume of fluid framework. The jet lengths, diameters, velocities, and temperatures were analysed as a function of the power-law non-Newtonian modification of reference water. It is observed that the jets under vacuum conditions are thinner for Newtonian and shear-thickening fluids than those in the atmosphere. The jet length increases from shear-thinning to shear-thickening rheology but is not affected by the pressure. The shear produced at the nozzle outlet is similar for both pressure conditions but increases in downstream directions for vacuum conditions. Gas expanding into vacuum cools by ~100-150 K while the temperature of the liquid jet drops only by a few K.

• Language: English
• Keywords: serial crystallography, flow-focusing, micro jets, fluid rheology, non-Newtonian fluid, flow focusing
• Work type: Article
• Typology: 1.08 - Published Scientific Conference Contribution
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2024
• Number of pages: 6 str.
• Numbering: Vol. 2766, art. 012069
• PID: 20.500.12556/RUL-158316
• UDC: 532:519.62
• ISSN on article: 1742-6596
• DOI: 10.1088/1742-6596/2766/1/012069
• COBISS.SI-ID: 197795843
• Publication date in RUL: 05.06.2024

Record is a part of a proceedings

• Title: Eurotherm 2024
• COBISS.SI-ID: 197654787

Record is a part of a journal

• Title: Journal of physics. Conference series
• Publisher: Institute of Physics Publishing
• ISSN: 1742-6596
• COBISS.SI-ID: 2035044

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: serijska femtosekundna kristalografija, mikro-curek, reologija toka, nenewtonska tekočina, fokusiranja toka