Modeling of Trace Knock in a Modern SI Engine Fuelled by Ethanol/Gasoline Blends University of Melbourne

Format:

Conference/Event

Author/Creator:

Yuanyuan, author.

Contributor:

Anderson, James E.

Brear, Michael

Ayuan

Foong, Tien Mun

Leone, Thomas

Yang, Yi

Conference Name:

SAE 2015 World Congress & Exhibition (2015-04-21 : Detroit, Michigan, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2015

Summary:

AbstractThis paper presents a numerical study of trace knocking combustion of ethanol/gasoline blends in a modern, single cylinder SI engine. Results are compared to experimental data from a prior, published work [1]. The engine is modeled using GT-Power and a two-zone combustion model containing detailed kinetic models. The two zone model uses a gasoline surrogate model [2] combined with a sub-model for nitric oxide (NO) [3] to simulate end-gas autoignition.Upstream, pre-vaporized fuel injection (UFI) and direct injection (DI) are modeled and compared to characterize ethanol's low autoignition reactivity and high charge cooling effects. Three ethanol/gasoline blends are studied: E0, E20, and E50. The modeled and experimental results demonstrate some systematic differences in the spark timing for trace knock across all three fuels, but the relative trends with engine load and ethanol content are consistent. Possible reasons causing the differences are discussed. Finally, the influence of NO on autoignition is investigated, yielding results that are consistent with prior works. Overall, the same, two-zone kinetic model appears to capture both the UFI and DI autoignition similarly well. These results also provide further evidence suggesting that inclusion of a NO sub-model is necessary for mechanistically accurate modeling of autoignition and knock in general

Notes:

Vendor supplied data

Publisher Number:

2015-01-1242

Access Restriction:

Restricted for use by site license