Characterization of the time-averaged overall heat transfer in a direct-injection hydrogen-fueled engine
Characterization of the time-averaged overall heat transfer in a direct-injection hydrogen-fueled engine
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DOI：
10.1016/j.ijhydene.2013.01.136
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发表时间：
2013-04
影响因子：
7.2
通讯作者：
M. Rahman;K. Hamada;A. Aziz
中科院分区：
文献类型：
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作者：
M. Rahman;K. Hamada;A. Aziz
本文对氢燃料直喷发动机的时均传热进行了研究。对缸内的整体传热过程进行了计算机模拟。实验结果验证了所采用的数值模型。一维气体动力学被用来描述在发动机模型的部件中的流动和传热。在改变发动机转速、当量比（φ）和喷射开始（SOI）正时的同时，分别对发动机模型进行了模拟，如下：上止点前1800 ≤ rpm ≤ 5000、0.2 ≤ φ ≤ 1.2和130° ≤ SOI ≤ 70°。通过试验结果验证了氢燃料发动机基准模型的正确性，并取得了较好的一致性。结果表明，当量比对时均传热特性有显著影响。这是一个独特的行为，出现在氢燃料发动机的情况下，由于广泛的可燃性范围。延迟喷射时刻会导致时均传热特性的不同表现。这表明燃烧非常差，因为在燃烧过程开始之前没有足够的时间进行燃料喷射。
This paper presents a description of the time-averaged heat transfer in a direct-injection hydrogen-fueled engine. A computer simulation of the overall heat transfer process within the in-cylinder was run. The experimental results were used to validate the adopted numerical model. One-dimensional gas dynamics were used to describe the flow and heat transfer in the components of the engine model. The engine model was simulated while varying the engine speed, equivalence ratio (φ), and start of injection (SOI) timing, respectively, as follows: 1800 ≤ rpm ≤ 5000, 0.2 ≤ φ ≤ 1.2, and 130° ≤ SOI ≤ 70° before top dead center. The baseline model of the hydrogen-fueled engine was verified through the experimental results, and reasonable agreement was achieved. The results show that the equivalence ratio has a significant impact on the time-averaged heat transfer characteristics. This is a unique behavior that appears in the case of hydrogen-fueled engines due to the wide flammability range. Delaying the injection timing caused different behavior of the time-averaged characteristics of heat transfer. This is an indication of remarkably poor combustion because there is insufficient time for fuel injection before the initiation of the combustion process.