Zhang Junqiang1£¬Tomio Obokata2£¬Seiichi Shiga2£¬Huang Zuohua1£¬Jiang Deming1
(1.State Key Laboratory of Multiphase Flow in Power Engineering,Xi'an Jiaotong University,Xi'an 710049,China;2.Department of Mechanical Engineering,Faculty of Engineering,Gunma University,Kiryu,Gunma 376-8515,Japan)
Abstract:Spray characteristics of flashing injection were investigated for kerosene containing dissolved methane through straight-rounded-hole nozzles by use of a particle size analyzer based on the narrowª²angle forward-scattering theory and a digital camera.The concentration of methane in kerosene was controlled by dissolving pressure,and the flashing phenomenon produced by separating dissolved methane was employed to improve atomization.The effects of concentration of dissolved methane£¬ measurement position,injection pressure,and length-to-diameter ratio of nozzle (L/D),on discharge coefficient,spray pattern,spray angle,and Sauter mean diameters were examined.The result shows that for different L/D nozzles the corresponding critical values of methane concentration exist.When a concentration is above the critical value the atomization is improved,and below the critical value the atomization is suppressed.Moreover,fuel spray angles increase dramatically due to the methane dissolved.In addition,the properties of gas-liquid two-phase flow inside nozzles have great influence on the spray characteristics of fuel containing dissolved gas£®
Keywords:spray characteristics;flashing injection;fuel dissolved gas;methane;kerosene