Flow visualisation in real-size optical injectors of conventional, additised, and renewable gasoline blends
Flow visualisation in real-size optical injectors of conventional, additised, and renewable gasoline blends
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DOI：
10.1016/j.enconman.2021.115109
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发表时间：
2022-01
影响因子：
10.4
通讯作者：
M. Heidari-Koochi;I. Karathanassis;P. Koukouvinis;Joonsik Hwang;L. Pickett;D. Spivey;M. Gavaises
中科院分区：
文献类型：
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作者：
M. Heidari-Koochi;I. Karathanassis;P. Koukouvinis;Joonsik Hwang;L. Pickett;D. Spivey;M. Gavaises
可再生和替代燃料的研究对于提高现代汽油内燃机的能源和环境效率至关重要。为了突出燃料流变学和热力学性质对相变和雾化过程的影响，测试了三种类型的汽油混合物。更具体地说，该活动包括参考汽油、代表可再生燃料的乙醇/汽油混合物（10%v/v）以及用粘弹诱导剂处理的添加剂汽油样品。采用漫反射背光照明技术对汽油喷油器内部几何结构和近喷嘴喷雾区域的瞬态两相流场进行了高速成像。商业喷油器的金属体进行了修改，以适应实现两个喷嘴布局，即一个两孔真实的尺寸的模型，类似于发动机燃烧网络喷雾G喷油器和愤怒的复制品与偏移孔的透明提示。在实际操作条件下进行实验，所述实际操作条件包括100巴的喷射压力和0.1-6.0巴范围内的环境压力，以覆盖汽油直喷式发动机中占主导地位的整个室压力范围。粘弹性添加剂的作用被证实对喷嘴内空化具有抑制作用（空化程度降低6%），同时还以类似于更易挥发的汽油/乙醇共混物的方式增强闪蒸条件下的喷雾雾化。最后，由于添加剂的表面活性剂性质，发现在添加剂的样品注射结束后形成持续的液体韧带。
Research on renewable and alternative fuels is crucial for improving the energy and environmental efficiency of modern gasoline internal combustion engines. To highlight the influence of fuel rheological and thermodynamic properties on phase change and atomisation processes, three types of gasoline blends were tested. More specifically, the campaign comprised a reference gasoline, an ethanol/gasoline blend (10% v/v) representative of renewable fuels, and an additised gasoline sample treated with viscoelasticity-inducing agents. High-speed imaging of the transient two-phase flow field arising in the internal geometry and the near-nozzle spray region of gasoline injectors was performed employing Diffuse Backlight Illumination. The metallic body of a commercial injector was modified to fit transparent tips realising two nozzle layouts, namely a two-hole real size model resembling the Engine Combustion Network spray G injector and an enraged replica with an offset hole. Experiments were conducted at realistic operating conditions comprising an injection pressure of 100 bar and ambient pressures in the range of 0.1–6.0 bar to cover the entire range of chamber pressures prevailing in Gasoline Direct Injection engines. The action of viscoelastic additives was verified to have a suppressive effect on in-nozzle cavitation (6% reduction in cavitation extent) , while also enhancing spray atomisation at flash-boing conditions, in a manner resembling the more volatile gasoline/ethanol blends. Finally, persisting liquid ligaments were found to form after the end of injection for the additised sample, owing to the surfactant nature of the additives.