2019 Fiscal Year Final Research Report
Predicted ignitability index based on the molecular structures of hydrocarbons for modern diesel combustion
| Project/Area Number |
17K06177
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Multi-year Fund |
|---|
| Section | 一般 |
|---|
| Research Field |
Thermal engineering
|
|---|
| Research Institution | Hokkaido University |
|---|
Principal Investigator |
|
|---|
| Project Period (FY) |
2017-04-01 – 2020-03-31
|
| Keywords | ディーゼルエンジン / 着火遅れ / セタン価 / アレニウス式 / 酸素濃度 / 温度 / 圧力 |
|---|
| Outline of Final Research Achievements |
To understand the dependence of ignition delay on the cetane number under various super-charging and EGR conditions in diesel combustion, ignition delays were systematically measured in a 0.83L single cylinder diesel engine. The investigations were conducted over a wide range of intake oxygen concentrations, intake gas temperatures, intake pressures, and cetane numbers to develop an empirical formula for the ignition delay based on the Arrhenius equation. The final proposed equation can adequately predict ignition delays with three parameters: the cetane number as well as the in-cylinder gas temperature and the oxygen partial pressure at the start of the fuel injection. The equation can predict ignition delays shorter than 2.0 ms, but the calculated ignition delays are longer than the experimental data when the ignitio delays exceed 2.0 ms. This is due to the earlier fuel injection timings with the longer ignition delay to maintain the ignition timing at TDC.
|
| Free Research Field |
エンジンシステム工学
|
| Academic Significance and Societal Importance of the Research Achievements |
ディーゼルエンジンにおける着火遅れは，機関性能および排気特性に対して大きな影響を与えるため，その把握はきわめて重要であるのに対して，広域かつ多様に変化するエンジン燃焼室内雰囲気条件と着火遅れとの関係を体系的に調査した例は少ない．広範な運転条件およびセタン価に対して適用可能な着火遅れ予測式を構築できれば，ディーゼルエンジンの高効率・高性能・低エミッション化に資する成果となることが期待できる．
|
