Soot mitigation potential of multiple injection strategies for fuel-rich combustion in compression-ignition engines
Abstract/Contents
- Abstract
- Conventional direct-injection, compression-ignition (DI/CI) engines operate at overall lean equivalence ratios (Phi < 0.7) to avoid excessive amounts of engine-out soot emissions. In order to overcome this equivalence ratio barrier, while keeping the soot levels low, oxygenated fuels (such as methanol and ethanol) have previously shown promising results in stoichiometric DI/CI combustion strategy. Although these fuels are difficult to autoignite, utilizing thermal barrier coatings on in-cylinder surfaces have resulted in reliable operation at stoichiometric conditions while keeping the soot emissions orders of magnitude below the soot levels for Diesel fuel. Moreover, these developments have enabled the use of DI/CI engines as work-producing, fuel-reforming devices operating at fuel-rich regimes. This work presents original data collected on single-cylinder, low-heat rejection (LHR), direct-injection, compression-ignition engine using ethanol and E85 (a mixture of 85% ethanol and 15% gasoline by volume) in stoichiometric to fuel-rich equivalence ratios. The equivalence ratio sweep data show that ethanol soot concentrations continue to increase up to an equivalence ratio of 1.4 and exhibit a plateau beyond this point. The E85 soot concentration profile shows a similar trend. However, compared to ethanol, the presence of longer chain hydrocarbon components and aromatics in the E85 increases the soot levels dramatically. The experiments in this study focus on investigating soot mitigation potential of multiple injection strategies for ethanol in fuel-rich and E85 in stoichiometric operations. Furthermore, the effects of multiple injection strategies on engine performance and other engine-out emissions in fuel-rich and stoichiometric equivalence ratios are discussed. Experimental findings show that it is possible to mitigate engine-out-soot by at least a factor of two without hindering the engine performance in both fuel-rich and stoichiometric DI/CI operation. In order to be able to interpret the experimental findings, a phenomenological model referred to as Multi-Zone NSL (MZ-NSL) model for DI/CI engines was developed to capture the in-cylinder inhomogeneity and to accommodate multiple injection operating conditions. The model was able to capture the trends of exhaust species and in-cylinder pressure of multiple injection experiments.
Description
| Type of resource | text |
|---|---|
| Form | electronic resource; remote; computer; online resource |
| Extent | 1 online resource. |
| Place | California |
| Place | [Stanford, California] |
| Publisher | [Stanford University] |
| Copyright date | 2024; ©2024 |
| Publication date | 2024; 2024 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Cetin, Burak Yunus |
|---|---|
| Degree supervisor | Edwards, C. F. (Christopher Francis) |
| Thesis advisor | Edwards, C. F. (Christopher Francis) |
| Thesis advisor | Kar, Kenneth C |
| Thesis advisor | Wang, Hai, 1962- |
| Degree committee member | Kar, Kenneth C |
| Degree committee member | Wang, Hai, 1962- |
| Associated with | Stanford University, School of Engineering |
| Associated with | Stanford University, Department of Mechanical Engineering |
Subjects
| Genre | Theses |
|---|---|
| Genre | Text |
Bibliographic information
| Statement of responsibility | Burak Yunus Cetin. |
|---|---|
| Note | Submitted to the Department of Mechanical Engineering. |
| Thesis | Thesis Ph.D. Stanford University 2024. |
| Location | https://purl.stanford.edu/sp065qq0694 |
Access conditions
- Copyright
- © 2024 by Burak Yunus Cetin
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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