Experimental investigation of direct injection charge cooling in optical GDI engine using tracer-based PLIF technique
Experimental investigation of direct injection charge cooling in optical GDI engine using tracer-based PLIF technique
复制标题
DOI：
10.1016/j.expthermflusci.2014.07.020
复制
发表时间：
2014-11
影响因子：
3.2
通讯作者：
M. A. Attar;Mohammad Reza Herfatmanesh;Hua Zhao;A. Cairns
中科院分区：
文献类型：
--
作者：
M. A. Attar;Mohammad Reza Herfatmanesh;Hua Zhao;A. Cairns
研究直喷充量冷却效果对于设计和开发汽油直喷（GDI）发动机新燃烧系统是必不可少的。进气冷却可用于增加发动机容积效率或压缩比。它可用于抑制高增压小型发动机的提前点火或自然吸气发动机的爆震燃烧。本工作的主要目的是开发一种实验装置，用于定量测量在GDI发动机燃烧室内的燃料喷射过程中的充电冷却与光学访问。为此，基于示踪剂的双线平面激光诱导荧光（PLIF）技术被实施用于测量。利用专门设计的定容室（CVC）进行准原位校准测量，从而可以独立于掺杂剂示踪剂的物理模型来实现缸内充气温度测量。通过测量发动机和点火循环的压缩冲程期间的平均缸内充气温度，并将结果与从假设多方压缩的缸内压力数据计算的温度值进行比较，来评估温度测量技术。PLIF技术被成功地用于量化由于90 °和250 °CA ATDC的两个喷射定时和10和30 mg/循环的两个喷射量的直接喷射充量冷却而导致的全局温度降低的程度。试验结果表明，两线PLIF测温技术的能力，在定量研究直接喷射充电冷却效果。
Investigation of direct injection charge cooling effects is indispensable in design and development of new combustion systems for Gasoline Direct Injection (GDI) engines. The charge cooling can be utilized to increase engine volumetric efficiency or compression ratio. It can be employed to suppress pre-ignition of highly boosted downsized engines or knocking combustion of naturally aspirated engines. The main purpose of this work was to develop an experimental setup for quantitative measurements of charge cooling during fuel injection process inside the combustion chamber of a GDI engine with optical access. For this purpose a tracer-based two-line Planar Laser Induced Fluorescence (PLIF) technique was implemented for the measurements. A specially designed Constant Volume Chamber (CVC) was utilized for quasi in situ calibration measurement so in-cylinder charge temperature measurements can be achieved independent of the photophysical model of dopant tracer. The thermometry technique was evaluated by measurements of average in-cylinder charge temperature during compression stroke for both motoring and firing cycles and comparing the results with temperature values calculated from in-cylinder pressure data assuming a polytropic compression. The PLIF technique was successfully utilized to quantify the extend of global temperature decrease as a result of direct injection charge cooling of two injection timings of 90 and 250 °CA ATDC and two injection quantities of 10 and 30 mg/cycle. Test results demonstrated the capability of the two-line PLIF thermometry technique in quantitative study of direct injection charge cooling effects.