An extended FGM model with transported PDF for LES of spray combustion
Hadadpour, Ahmad LU ; Xu, Shijie LU
; Zhang, Yan
LU
; Bai, Xue Song
LU
and Jangi, Mehdi
LU
(2023)
In Proceedings of the Combustion Institute
39(4).
p.4889-4898
- Abstract
An enhanced flamelet generated manifold (FGM) model for large eddy simulation (LES) of turbulent spray combustion is presented. In the enhanced FGM model, a transported probability density function (TPDF) description of the FGM variables is employed. The TPDF is represented using the Eulerian stochastic fields (ESF) approach, and the method is applied to LES of spray combustion under conditions relevant to internal combustion engines. The new ESF/FGM method achieves an improved accuracy of predictions due to the ESF modelling of the subgrid-scale turbulence-chemistry interaction. It also achieves high computational efficiency due to the FGM tabulation of the chemical kinetic mechanism. The performance of the new ESF/FGM model is... (More)
An enhanced flamelet generated manifold (FGM) model for large eddy simulation (LES) of turbulent spray combustion is presented. In the enhanced FGM model, a transported probability density function (TPDF) description of the FGM variables is employed. The TPDF is represented using the Eulerian stochastic fields (ESF) approach, and the method is applied to LES of spray combustion under conditions relevant to internal combustion engines. The new ESF/FGM method achieves an improved accuracy of predictions due to the ESF modelling of the subgrid-scale turbulence-chemistry interaction. It also achieves high computational efficiency due to the FGM tabulation of the chemical kinetic mechanism. The performance of the new ESF/FGM model is assessed by simulation of the Spray-A flames from Engine Combustion Network (ECN) and comparison of the results, firstly, with experimental measurements, and secondly, with conventional FGM model simulation results. It is shown that the ESF/FGM method is capable of predicting both global and local combustion characteristics, i.e., pressure rise, ignition delay time, flame lift-off length and the thermo-chemical structure of the spray flames with improved accuracy compared to the conventional FGM model that is based on the presumed PDF description of FGM variables. The sensitivity of the predictions using ESF/FGM to the number of stochastic fields is examined by varying the number of these fields in the range of 4-128. Furthermore, the influence of different FGM reaction progress variables on the simulations is investigated, and a new reaction progress variable based on the local consumption of oxygen is proposed. The results show that the new progress variable improves predictions of spray combustion, including the prediction of the start of injection, the quasi-steady state liftoff length, the post-injection oxidation, and the pressure evolution.
(Less)
- author
- Hadadpour, Ahmad
LU
; Xu, Shijie
LU
; Zhang, Yan
LU
; Bai, Xue Song
LU
and Jangi, Mehdi
LU
- organization
- publishing date
- 2023
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Engine combustion network (ECN), Eulerian stochastic fields (ESF), Flamelet generated manifold (FGM), LES, Reaction progress variable, Spray combustion
- in
- Proceedings of the Combustion Institute
- volume
- 39
- issue
- 4
- pages
- 4889 - 4898
- publisher
- Elsevier
- external identifiers
-
- scopus:85140843243
- ISSN
- 1540-7489
- DOI
- 10.1016/j.proci.2022.09.014
- language
- English
- LU publication?
- yes
- additional info
- .
- id
- 057a7a93-e745-4363-8367-3efbf75d4560
- date added to LUP
- 2023-01-16 10:04:59
- date last changed
- 2023-11-20 16:38:54
@article{057a7a93-e745-4363-8367-3efbf75d4560,
abstract = {{<p>An enhanced flamelet generated manifold (FGM) model for large eddy simulation (LES) of turbulent spray combustion is presented. In the enhanced FGM model, a transported probability density function (TPDF) description of the FGM variables is employed. The TPDF is represented using the Eulerian stochastic fields (ESF) approach, and the method is applied to LES of spray combustion under conditions relevant to internal combustion engines. The new ESF/FGM method achieves an improved accuracy of predictions due to the ESF modelling of the subgrid-scale turbulence-chemistry interaction. It also achieves high computational efficiency due to the FGM tabulation of the chemical kinetic mechanism. The performance of the new ESF/FGM model is assessed by simulation of the Spray-A flames from Engine Combustion Network (ECN) and comparison of the results, firstly, with experimental measurements, and secondly, with conventional FGM model simulation results. It is shown that the ESF/FGM method is capable of predicting both global and local combustion characteristics, i.e., pressure rise, ignition delay time, flame lift-off length and the thermo-chemical structure of the spray flames with improved accuracy compared to the conventional FGM model that is based on the presumed PDF description of FGM variables. The sensitivity of the predictions using ESF/FGM to the number of stochastic fields is examined by varying the number of these fields in the range of 4-128. Furthermore, the influence of different FGM reaction progress variables on the simulations is investigated, and a new reaction progress variable based on the local consumption of oxygen is proposed. The results show that the new progress variable improves predictions of spray combustion, including the prediction of the start of injection, the quasi-steady state liftoff length, the post-injection oxidation, and the pressure evolution.</p>}},
author = {{Hadadpour, Ahmad and Xu, Shijie and Zhang, Yan and Bai, Xue Song and Jangi, Mehdi}},
issn = {{1540-7489}},
keywords = {{Engine combustion network (ECN); Eulerian stochastic fields (ESF); Flamelet generated manifold (FGM); LES; Reaction progress variable; Spray combustion}},
language = {{eng}},
number = {{4}},
pages = {{4889--4898}},
publisher = {{Elsevier}},
series = {{Proceedings of the Combustion Institute}},
title = {{An extended FGM model with transported PDF for LES of spray combustion}},
url = {{http://dx.doi.org/10.1016/j.proci.2022.09.014}},
doi = {{10.1016/j.proci.2022.09.014}},
volume = {{39}},
year = {{2023}},
}