Experiment on flash-boiling spray characteristics of single-orifice/dual-orifice nozzle
The flash-boiling spray characteristics of RP-3 aviation kerosene inside single-orifice/dual-orifice nozzle were experimentally studied to analyze the influence of superheat degree and nozzle structural parameters on in-nozzle flow and near-nozzle jet.Results showed that increasing the length-diameter ratio of single-orifice nozzle can inhibit the cavitation effect inside the nozzle,helping to increase the kerosene gasification rate from wall boiling inside the nozzle,resulting in better atomization effect of fuel jet.The expansion chamber of dual-orifice nozzle could play the role of increasing the discharge-orifice's gasification rate;however,excessive aspect ratio of expansion chamber may decrease the superheat degree inside the nozzle,which impaired the near-nozzle atomization effect and spray symmetry.Compared with single-orifice nozzle,dual-orifice nozzle allows more easily to promote the transformation of aviation kerosene from subcooled spray to flash-boiling spray by increasing the residence time for phase transition,helping to improve the fuel atomization and obtain larger spray width and spray cone angle.Thus,using dual-orifice nozzle is a potential technical way to realize flash-boiling spray in the combustion chamber of aero-engine.
single-orifice/dual-orifice nozzleflash-boiling sprayaviation kerosenein-nozzle two-phase flownear-nozzle jetspray correlation index
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