1 research outputs found
Fundamental analysis of liquid breakup mechanism in a rotary atomizer with square discharge orifice
[EN] An experimental investigation of breakup mechanism in a rotary atomizer with square shape discharge orifice at
ambient condition has been performed. The effects of a high aspect ratio noncircular discharge channels,
particularly a square shape discharge channel, are considered. The motivation of this study is the use of this type
of orifice in some small gas turbine engines as well as non-existing observation in literature concerning about high
aspect ratio of discharge channel. Visualization experiments are conducted by high speed shadowgraph imaging
technique with pulsed light illumination for the first time. The effects of rotational speed and volume flow rate are
studied on the breakup structure. The visualizations indicates that the liquid film formed along the channel is pushed
to one side of it due to Coriolis force which is dominant in this type of atomizer. Accordingly a crescent shaped liquid
film is formed at the square channel exit covering two corners of the square, resulting the combination of Coriolis
induced stream mode and surface tension induced stream mode breakup. Observations of the breakup process for
different volume flow rates and rotational speeds indicate that the breakup of liquid film stream is dependent on
injection conditions and the corresponding cross flow velocity created by atomizer rotation. The breakup regime
map is provided as a function of weber number and momentum flux ratio. Four distinct regimes are identified:
Rayleigh breakup, bag breakup, multimode breakup, and shear breakup. The present results leads to understanding
atomization performance and creating some idea to improved spray quality in this type of atomizer.Ghorbanhoseini, M.; Rezayat, S.; Farshchi, M. (2017). Fundamental analysis of liquid breakup mechanism in a rotary atomizer with square discharge orifice. En Ilass Europe. 28th european conference on Liquid Atomization and Spray Systems. Editorial Universitat Politècnica de València. 496-503. https://doi.org/10.4995/ILASS2017.2017.5640OCS49650