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Faculty of Mechanical Engineering, Lj. (FSLJ)
  • Experimental and numerical investigation of gas-focused liquid micro-jet velocity
    Zahoor, Rizwan ...
    Compressible multiphase numerical simulations of gas-focused micro-jets are compared with the experimental data obtained with the dual pulse imaging laser-induced fluorescence drop velocimetry. Such ... jets, originating from a 3D printed gas dynamic virtual nozzle into a low-vacuum (150 Pa) environment, are increasingly being used for sample delivery in serial femtosecond crystallography. The distance traveled by a detaching drop from the jet is measured between the two consecutive illumination pulses with a known time delay at the positions 200 [micro]m and 450 [micro]m from the nozzle. Additionally, the high-speed camera images are used to analyze the shape of the jet. An axisymmetric, compressible, Newtonian two-phase helium-water mixture model is numerically solved within the framework of the volume of fluid and the finite volume method. The experimental and the computational studies are performed with a constant volumetric liquid flow rate of 14 [micro]l/min and the gas mass flow rate in the range from 4.6 mg/min to 20 mg/min. The related jet Reynolds number ranges from 120 to 220 and Weber number from 30 to 150. The maximum difference between the measurements and the results of the numerical model in terms of the droplet velocity and jet diameter is within 10 %. The study provides new information on the jet velocities for micron-sized gas-focused nozzles. The validated numerical model can be used as a design tool for the nozzles dedicated to the specific needs of the femtosecond crystallography experiments.
    Source: International journal of multiphase flow. - ISSN 0301-9322 (Vol. 135, Feb. 2021, str. 1-13)
    Type of material - article, component part
    Publish date - 2021
    Language - english
    COBISS.SI-ID - 41249283