Imaging and heat flux measurements of wall impinging sprays of hydrocarbons and alcohols in a direct-injection spark-ignition engine
Imaging and heat flux measurements of wall impinging sprays of hydrocarbons and alcohols in a direct-injection spark-ignition engine
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DOI：
10.1016/j.fuel.2011.07.037
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发表时间：
2012-01-01
期刊：
影响因子：
7.4
通讯作者：
Richardson, D.
中科院分区：
文献类型：
--
作者：
Serras-Pereira, J.;Aleiferis, P. G.;Richardson, D.
用于直喷式火花点火发动机的最新一代燃料系统使用容纳具有各种角度的多个孔的喷嘴，以便在发动机操作条件范围内提供缸内燃料目标的灵活性。然而，有效的燃料雾化所需的高喷射压力可能导致与液体燃料冲击到活塞和衬套壁上的发动机废气排放（例如，未燃烧的碳氢化合物和颗粒）有关的恶化效果。消除这种恶化的影响需要对缸内喷雾发展过程有基本的了解，同时考虑到未来商业燃料的多样性，这些燃料可能含有大量的生物组分，这些生物组分具有与典型液态烃非常不同的化学和物理特性。本文介绍了高速成像结果的喷雾撞击到衬套的直喷火花点火发动机，以及曲柄角分辨壁面热流密度测量在观察到的位置的燃料撞击的水平和时间的详细特征的冲击。这些测试是在1500 RPM的运行发动机中进行的，主要是在低负荷（0.5巴进气压力）下，使用20、50和90摄氏度的发动机温度。汽油、异辛烷、丁醇、乙醇和10%乙醇与90%汽油的混合物（E10）被用于包含用于火花点火发动机的一系列当前和未来燃料组分。收集的数据进行了分析，以提取平均值和标准偏差统计的喷雾图像和热通量信号。结果还解释了参考的物理性质和蒸发速率预测的一个单一的液滴模型的所有燃料测试。(C)2011爱思唯尔有限公司保留所有权利。
The latest generation of fuel systems for direct-injection spark-ignition engines uses injection nozzles that accommodate a number of holes with various angles in order to offer flexibility in in-cylinder fuel targeting over a range of engine operating conditions. However, the high-injection pressures that are needed for efficient fuel atomisation can lead to deteriorating effects with regards to engine exhaust emissions (e.g. unburned hydrocarbons and particulates) from liquid fuel impingement onto the piston and liner walls. Eliminating such deteriorating effects requires fundamental understanding of in-cylinder spray development processes, taking also into account the diversity of future commercial fuels that can contain significant quantities of bio-components with very different chemical and physical properties to those of typical liquid hydrocarbons. This paper presents high-speed imaging results of spray impingement onto the liner of a direct-injection spark-ignition engine, as well as crank-angle resolved wall heat flux measurements at the observed locations of fuel impingement for detailed characterisation of levels and timing of impingement. The tests were performed in a running engine at 1500 RPM primarily at low load (0.5 bar intake pressure) using 20, 50 and 90 degrees C engine temperatures. Gasoline, iso-Octane, Butanol, Ethanol and a blend of 10% Ethanol with 90% Gasoline (E10) were used to encompass a range of current and future fuel components for spark-ignition engines. The collected data were analysed to extract mean and standard deviation statistics of spray images and heat flux signals. The results were also interpreted with reference to physical properties and evaporation rates predicted by a single droplet model for all fuels tested. (C) 2011 Elsevier Ltd. All rights reserved.