| Autor: |
Akira Iijima, Shuhei Takahata, Hiroki Kudo, Keito Agui, Masaaki Togawa, Kento Shimizu, Yuki Takamura, Mitsuaki Tanabe, Hideo Shoji |
| Jazyk: |
angličtina |
| Rok vydání: |
2018 |
| Předmět: |
|
| Zdroj: |
International Journal of Automotive Engineering, Vol 9, Iss 1, Pp 23-30 (2018) |
| Druh dokumentu: |
article |
| ISSN: |
2185-0992 |
| DOI: |
10.20485/jsaeijae.9.1_23 |
| Popis: |
In this study, knocking over a wide range of engine speeds was visualized using an optically acssessible engine. In addition, knock under a high compression ratio and supercharged, lean combustion was investigated. The results revealed that under high-speed knock, the flame propagation velocity declined when low-temperature oxidation reactions occurred. Subsequently, autoignition began locally and expanded gradually. Eventually, it was observed that a highly brilliant autoignited flame appeared and propagated through the unburned end gas at a high speed of approximately 1700-1800 m/s. This suggests that high-speed knock causes “developing detonation” in which combustion proceeds at a supersonic speed while pressure waves and the reaction front mutually interact. It was also found that strong knock occurred under supercharged, ultra-lean conditions (Compression Ratio: CR=14, Equivalence Ratio: Φ =0.5, Intake Pressure: Pin = 140 kPa). In addition, the application of exhaust gas recirculation markedly reduced strong pressure oscillations. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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