Projects per year
Abstract
The flame initiation process in dual-fuel spray assisted combustion is presently not fully understood. Here, diesel spray assisted combustion of premixed methane/oxidizer/EGR is explored in the post-ignition phase by scale-resolved simulations. The modified dual-fuel ECN Spray A forms the baseline configuration. An extensive local grid refinement (approaching DNS limit) around one of the first high-temperature ignition kernels is carried out in order to examine the validity of hypothesized flame initiation and deflagration. A high quality LES is used to solve the spray dynamics, while the embedded quasi-DNS (eq-DNS) region offers detailed information on the ignition kernel evolution. The finite-rate chemistry is directly integrated, utilizing 54 species and 269 reactions. Local combustion modes are investigated for the ignition kernel development toward spontaneous ignition and premixed flame propagation using various approaches, including the reaction front displacement speed, energy transport budget, and chemical explosive mode analysis. Furthermore, a new criterion based on reaction flux analysis is introduced, which is compatible with dual-fuel combustion. The spatial and temporal scales associated with the ambient methane consumption and consequent flame initiation are characterized. For the first time in dual-fuel spray assisted simulations, numerical evidence is provided on the initiation of premixed flames, and the corresponding timescale is reported. Particularly, there is a transient mixed-mode combustion phase of approximately 0.2 ms after the spray second stage ignition wherein extinction, ignition fronts, and quasi-deflagrative structures co-exist. After such a transient period, the combustion mode becomes essentially deflagrative. Finally, interactions between turbulence and premixed flame front are characterized mostly in the corrugated regime.
Original language | English |
---|---|
Article number | 113172 |
Journal | Combustion and Flame |
Volume | 259 |
DOIs | |
Publication status | Published - Jan 2024 |
MoE publication type | A1 Journal article-refereed |
Keywords
- Auto-ignition
- Deflagration
- Direct numerical simulation
- Dual-fuel
- Large-eddy simulation
- Spray
Fingerprint
Dive into the research topics of 'Embedded direct numerical simulation of ignition kernel evolution and flame initiation in dual-fuel spray assisted combustion'. Together they form a unique fingerprint.Projects
- 3 Finished
-
Cool/Kaario: Reacting flow near cool walls
Kaario, O. (Principal investigator), Tamadonfar, P. (Project Member), Salomaa, V.-P. (Project Member), Tamadonfar, P. (Project Member), Shahanaghi, A. (Project Member), Celik, H. (Project Member), Yeganeh, M. (Project Member), Cheng, Q. (Project Member), Shahin, Z. (Project Member), Kilic, C. (Project Member) & Kapp, J. (Project Member)
01/09/2020 → 31/08/2024
Project: Academy of Finland: Other research funding
-
DIAG/Karimkashi: Multi-fuel combustion: development of a diagnostic tool for carbon-neutral combustion
Karimkashi Arani, S. (Principal investigator)
01/09/2020 → 31/08/2023
Project: Academy of Finland: Other research funding
-
Tri-Reactivity Ignition: Simulation and Experiments
Vuorinen, V. (Principal investigator), Morev, I. (Project Member), Cheng, Q. (Project Member), Tamadonfar, P. (Project Member), Gadalla, M. (Project Member) & Kannan, J. (Project Member)
01/09/2018 → 31/08/2022
Project: Academy of Finland: Other research funding
Press/Media
-
Studies in the Area of Mathematics Reported from Aalto University (Embedded Direct Numerical Simulation of Ignition Kernel Evolution and Flame Initiation In Dual-fuel Spray Assisted Combustion)
05/01/2024
1 item of Media coverage
Press/Media: Media appearance