%0 Journal Article %A Aori, Gele %A Hung, David L. S. %A Zhang, Ming %A Zhang, Gaomimg %A Li, Tianyun %D 2016 %I Begell House %K multi-hole injector, superheated spray, flash boiling, macroscopic spray characteristics %N 5 %P 439-462 %R 10.1615/AtomizSpr.2015011990 %T EFFECT OF NOZZLE CONFIGURATION ON MACROSCOPIC SPRAY CHARACTERISTICS OF MULTI-HOLE FUEL INJECTORS UNDER SUPERHEATED CONDITIONS %U https://www.dl.begellhouse.com/journals/6a7c7e10642258cc,2a21aa19478d55c2,34c3b5e3382ff6ae.html %V 26 %X The effect of nozzle configuration on the macroscopic spray structures of multi-hole fuel injectors under superheated conditions is investigated. Nine prototype multi-hole fuel injectors with various nozzle tip configurations, including hole diameter, hole exit angle, hole shape, hole-to-hole distance, and length-to-diameter (L/D), were custom made for this investigation. A high-speed backlit imaging system was used to image the axial spray characteristics along the injector axis and a planar Mie scattering optical patternation method was performed to analyze the cross-sectional spray patterns at various distances below the injector tip. Experimental results reveal that the superheated degree, which is quantified by the ambient-to-saturation pressure ratio (Pa/Ps), significantly influences the macroscopic structure of emerging liquid plumes from nozzle holes. The interactions among individual plumes are closely coupled with the design of the nozzle configuration. The nozzle hole angle orientation and number of holes are the main factors which influence the axial and cross-sectional distributions of overall spray structure. The structural transformation of spray characteristics under superheated conditions is more pronounced for an injector with more holes arranged in a symmetric configuration due to the stronger interactions among adjacent plumes. Therefore, by considering the influences of superheated degree and plume-to-plume interaction, a better understanding towards the flash-boiling behavior of multi-hole injector spray can be revealed. %8 2016-01-12