Abstract
Lagrangian particle tracking and Large-Eddy simulation were used to assess the effect of different fuels on spray characteristics. In such a two-way coupled modeling scenario, spray momentum accelerates the gaseous phase into an intense, multiphase jet near the nozzle. To assess fuel property effects on liquid spray formation, the non-reacting Engine Combustion Network Spray A baseline condition was chosen as the reference case. The validated Spray A case was modified by replacing n-dodecane with diesel, methanol, dimethyl ether, or propane assuming 150 MPa injection pressure. The model features and performance for various fuels in the under-resolved near-nozzle region are discussed. The main findings of the paper are as follows. (1) We show that, in addition to the well-known liquid penetration (Formula presented.), and vapor penetration (Formula presented.), for all the investigated fuels, the modeled multiphase jets exhibit also a third length scale (Formula presented.), with discussed correspondence to a potential core part common to single phase jets. (2) As a characteristic feature of the present model, (Formula presented.) is noted to correlate linearly with (Formula presented.) and (Formula presented.) for all the fuels. (3) A separate sensitivity test on density variation indicated that the liquid density had a relatively minor role on (Formula presented.). (4) Significant dependency between fuel oxygen content and the equivalence ratio (Formula presented.) distribution was observed. (5) Repeated simulations indicated injection-to-injection variations below 2% for (Formula presented.) and 4% for (Formula presented.). In the absence of experimental and fully resolved numerical near-nozzle velocity data, the exact details of (Formula presented.) remain as an open question. In contrast, fuel property effects on spray development have been consistently explained herein.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 26-42 |
| Number of pages | 17 |
| Journal | International Journal of Engine Research |
| Volume | 21 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jun 19 2019 |
Bibliographical note
KAUST Repository Item: Exported on 2020-10-01Acknowledged KAUST grant number(s): OSR-2017-3319
Acknowledgements: The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the European Union HERCULES-2 project within Horizon 2020 research and innovation program under grant agreement no. 634135. The present study has also been financially supported by the Academy of Finland (grant nos 289592 and 318024) and by the King Abdullah University of Science and Technology, Office of Sponsored Research (OSR) under Award OSR-2017-3319. The simulations presented above were performed using computer resources within the Aalto University School of Science “Science-IT” project.