%0 Journal Article %A Ku, Kun Woo %A Hong, Jung Goo %A Lee, Choong-Won %D 2011 %I Begell House %K elliptical nozzle, aspect ratio, cavitating flow, discharge coefficient, SMD %N 8 %P 655-672 %R 10.1615/AtomizSpr.2012004192 %T EFFECT OF INTERNAL FLOW STRUCTURE IN CIRCULAR AND ELLIPTICAL NOZZLES ON SPRAY CHARACTERISTICS %U https://www.dl.begellhouse.com/journals/6a7c7e10642258cc,13136d0f5643faad,573da4533ecc75aa.html %V 21 %X An experimental study was performed to investigate the atomization characteristics of a circular nozzle and elliptical nozzles of small diameter under high injection pressure, which has a hydraulic flip condition for the nozzle internal flow structure. The flow rate and drop size characteristics were measured for various injection pressures. Numerical simulations were attempted to investigate the internal flow structure in the circular and elliptical nozzles because the experimental study was limited in its measurements of flow velocity distributions, pressure distributions, and streamlines in the relatively small orifices. This study showed that the disintegration characteristics of the liquid jet of the elliptical nozzles were very different from those of the circular nozzle. In the case of the elliptical nozzles, the liquid jet became more unstable at the same injection pressure, unlike that of the circular nozzle. Surface breakup was observed at the jet issued from the elliptical nozzles with the increase of injection pressure. Furthermore, the numerical simulations informed that the internal flow structure of the elliptical nozzle was quite different from that of the circular nozzle. In the case of the circular nozzle, as with much of the literature on the internal flow structure of the hydraulic flip, the flow detached from the orifice wall. However, the internal flow structure of the elliptical nozzle in hydraulic flip was reattached to the orifice wall of the minor axis, unlike the flow in the circular nozzle. It has been concluded that the internal flow structure of the elliptical nozzle has influence on the disintegration characteristics of the liquid jet issued from the elliptical nozzle. %8 2012-02-24