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

Abstract

In this paper we present a numerical study investigating the effects of nozzle geometry on stability, shape and flow characteristics of micron-sized liquid jets, produced by injection molded gas dynamic virtual nozzles (GDVNs) operating in vacuum. The jet characteristics are described as a function of (i) capillary-to-orifice distance, (ii) nozzle outlet orifice diameter, and (iii) liquid feeding capillary angle. An experimentally verified numerical model of GDVN with laminar two-phase Newtonian compressible flow, based on finite volume method and volume of fluid interface tracking, is used to assess the changes. The study is performed for two sets of liquid flow rates while keeping the gas flow rate constant. It is observed that for each value of capillary-to-orifice distance and nozzle outlet diameter there is a minimum liquid flow rate below which the jet is unstable. We find that the nozzle outlet diameter has the biggest influence on the jet diameter, length and velocity, while liquid capillary angle has no observable effect on jet characteristic. Varying capillary-to-orifice distance does not affect the flow field around micro-jet. It is found that the liquid and the gas interaction near the meniscus primarily affect the jet stability and shape

Keywords

gas dynamic virtual nozzle;micro-jet;compressible multiphase flow;finite volume method;volume of fluid;

Data

Language: English
Year of publishing:
Typology: 1.01 - Original Scientific Article
Organization: UNG - University of Nova Gorica
UDC: 53
COBISS: 5124347 Link will open in a new window
ISSN: 0301-9322
Views: 4216
Downloads: 0
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Other data

URN: URN:SI:UNG
Type (COBISS): Not categorized
Pages: str. 152-165
Issue: ǂVol. ǂ104
Chronology: 2018
DOI: 10.1016/j.ijmultiphaseflow.2018.03.003
ID: 10914063