An analysis of spray development with iso-octane, n-pentane, gasoline, ethanol and n-butanol from a multi-hole injector under hot fuel conditions
An analysis of spray development with iso-octane, n-pentane, gasoline, ethanol and n-butanol from a multi-hole injector under hot fuel conditions
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DOI：
10.1016/j.fuel.2012.07.044
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发表时间：
2013-03-01
期刊：
影响因子：
7.4
通讯作者：
van Romunde, Z. R.
中科院分区：
文献类型：
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作者：
Aleiferis, P. G.;van Romunde, Z. R.
用于直喷式火花点火发动机的高压多孔喷油器在燃油雾化方面具有一些巨大的优势，并且通过选择喷嘴孔的数量和角度来灵活地定位燃油。然而，代表发动机使用各种燃料运行的喷射器本体温度的数据非常少，特别是在采用早期喷射策略的低负载条件下，这也可能由于喷射时的燃料闪蒸而导致相变。由于预测的燃料库存将包括重要的生物衍生成分，因此需要管理燃料灵活性，这一挑战变得更加复杂。生物成分（如各种类型的醇）的物理/化学性质可能与汽油显着不同，因此通过与液态碳氢化合物直接比较来研究其影响非常重要。这项工作概述了对燃料特性、温度和压力条件对喷雾形成程度影响的光学研究（高速成像和液滴尺寸）的结果。具体而言，在 20、50、90 和 120 摄氏度的喷油器本体温度、0.5 巴和 1.0 巴的环境压力下对汽油、异辛烷、正戊烷、乙醇和正丁醇进行了测试，以模拟部分负载和节气门全开发动机运行的早期均质喷射策略；一些测试也在180摄氏度、0.3巴下进行。还使用相位多普勒和激光衍射技术对汽油、异辛烷和正戊烷进行了液滴分级，以了解低挥发性和高挥发性组分对多组分汽油雾化的影响。获得了所有燃料的沸点和蒸馏曲线、蒸气压和泡点以及密度、粘度和表面张力，并在分析中考虑了雷诺数、韦伯数和Ohnesorge数。 (C) 2012 Elsevier Ltd. 保留所有权利。
High-pressure multi-hole injectors for direct-injection spark-ignition engines offer some great benefits in terms of fuel atomisation, as well as flexibility in fuel targeting by selection of the number and angle of the nozzle's holes. However, very few data exist for injector-body temperatures representative of engine operation with various fuels, especially at low-load conditions with early injection strategies that can also lead to phase change due to fuel flash boiling upon injection. The challenge is further complicated by the predicted fuel stocks which will include a significant bio-derived component presenting the requirement to manage fuel flexibility. The physical/chemical properties of bio-components, like various types of alcohols, can differ markedly from gasoline and it is important to study their effects in direct comparison to liquid hydrocarbons. This work outlines results from an optical investigation (high-speed imaging and droplet sizing) into the effects of fuel properties, temperature and pressure conditions on the extent of spray formation. Specifically, gasoline, iso-octane, n-pentane, ethanol and n-butanol were tested at 20, 50, 90 and 120 degrees C injector body temperatures for ambient pressures of 0.5 bar and 1.0 bar in order to simulate early homogeneous injection strategies for part-load and wide open throttle engine operation; some test were also carried out at 180 degrees C, 0.3 bar. Droplet sizing was also performed for gasoline, isooctane and n-pentane using Phase Doppler and Laser Diffraction techniques in order to understand the effects of low-and high-volatility components on the atomisation of the multi-component gasoline. The boiling points and distillation curves of all fuels, their vapour pressures and bubble points, as well as density, viscosity and surface tension were obtained and the Reynolds, Weber and Ohnesorge numbers were considered in the analysis. (C) 2012 Elsevier Ltd. All rights reserved.