Riupassa Helen, Marianingsih Susi, Nanlohy Hendry Y
Department of Mechanical Engineering, Jayapura University of Science and Technology, 99351, Indonesia.
Faculty of Computer Science and Management, Jayapura University of Science and Technology, 99351, Indonesia.
Heliyon. 2023 Jan 12;9(1):e12922. doi: 10.1016/j.heliyon.2023.e12922. eCollection 2023 Jan.
The effect of various ignition timing on spark ignition (SI) engines with bioethanol-isooctane mixtures has been widely studied. In the present studies, we used three different ignition angle positions, namely 9°, 12°, and 15° BTDC to increase the combustion pressure in the combustion chamber. In addition to macroscopic observations through engine performance, observations are also carried out from a molecular perspective, i.e.; atomic, bond, and bond angle properties of bioethanol-isooctane fuel. The result shows that more atoms of the isooctane carbon chain are non-rotatable (23 atomic bonds) than the 8 bonds of the bioethanol carbon chain. Furthermore, isooctane also has a wider bond angle (around 121.1745°) than the bond angle of ethanol (around 110.0476°). The unique properties of the atoms in the carbon chains of these two fuels have a direct impact on engine performance. The results show that the viscosity of bioethanol is lower when compared to isooctane, which indicates that the bioethanol molecules are more reactive and flammable. The result also found that at an ignition angle of 12° the BE50 engine has the best performance. Moreover, the test results also show that bioethanol produces clean combustion as evidenced by the lowest CO and HC gas emissions.
各种点火正时对使用生物乙醇 - 异辛烷混合物的火花点火（SI）发动机的影响已得到广泛研究。在本研究中，我们使用了三个不同的点火角位置，即上止点前9°、12°和15°，以增加燃烧室内的燃烧压力。除了通过发动机性能进行宏观观察外，还从分子角度进行观察，即生物乙醇 - 异辛烷燃料的原子、键和键角特性。结果表明，异辛烷碳链中不可旋转的原子（23个原子键）比生物乙醇碳链的8个键更多。此外，异辛烷的键角（约121.1745°）也比乙醇的键角（约110.0476°）更宽。这两种燃料碳链中原子的独特性质对发动机性能有直接影响。结果表明，与异辛烷相比，生物乙醇的粘度较低，这表明生物乙醇分子更具反应性和可燃性。结果还发现，在12°的点火角下，BE50发动机具有最佳性能。此外，测试结果还表明，生物乙醇产生清洁燃烧，这由最低的一氧化碳和碳氢化合物气体排放证明。
