Investigation of mixture formation in a diesel spray by tracer-based laser-induced fluorescence using 1-methylnaphthalene
Investigation of mixture formation in a diesel spray by tracer-based laser-induced fluorescence using 1-methylnaphthalene
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DOI：
10.1016/j.proci.2016.07.034
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
S. Lind;U. Retzer;S. Will;L. Zigan
中科院分区：
文献类型：
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作者：
S. Lind;U. Retzer;S. Will;L. Zigan
本文提出了一种基于示踪剂的平面激光诱导荧光（Tracer-PLIF）的柴油喷雾温度和燃油局部密度同时成像的原理验证研究。1-甲基萘（1-MN）的荧光在流动池中相对于温度和压力在氮气氛中在IC发动机条件下以266 nm激发来表征。1-MN随温度升高而发生的强光谱红移被用于双色LIF。仅用一个检测通道来确定燃料部分密度。该技术被进一步应用于研究在5 MPa和800 K的喷射室中的柴油喷雾的温度和燃料的局部密度的调查。平均图像的先导喷射揭示了燃料射流和周围环境之间的最大温差约为150 K，最大燃料局部密度约为220 g/m3。在可见喷射开始后的1300至1700 µs之间，混合温度升高高达50 K，由于气体夹带，燃料部分密度降低约20 g/m3。通过研究周期性喷雾变化，进一步证明了LIF技术用于单次测量的适用性，这允许详细了解IC发动机燃烧中混合物的形成。这种基于示踪剂的增强型LIF技术首次允许在高温下同时量化温度和燃料部分密度，这与柴油发动机高度相关。
The paper presents a proof-of-principle study for the simultaneous imaging of temperature and fuel partial density in a realistic diesel spray using tracer-based planar laser-induced fluorescence (Tracer-PLIF). The fluorescence of 1-methylnaphthalene (1-MN) is characterized in a flow cell with respect to temperature and pressure in nitrogen atmosphere at IC engine conditions with excitation at 266 nm. The strong spectral red-shift of 1-MN with increasing temperature is used for two-color-LIF. The fuel partial density is determined with only one detection channel. This technique is further applied for investigation of temperature and fuel partial density in a diesel spray studied at 5 MPa and 800 K in an injection chamber. Averaged images are presented for a pilot injection revealing a maximum temperature difference between fuel jet and ambience of about 150 K with a maximum fuel partial density of about 220 g/m3. Between 1300 and 1700 µs after visible start of injection, the mixing temperature increases by up to 50 K and the fuel partial density decreases by about 20 g/m3because of gas entrainment. The suitability of the LIF technique for single-shot measurements is further demonstrated by studying the cyclic spray variations, which allows for a detailed understanding of mixture formation in IC engine combustion. This enhanced tracer-based LIF-technique for the first time allows for a simultaneous quantification of temperature and fuel partial density at elevated temperatures, which are highly relevant for diesel engines.