An extended FGM model with transported PDF for LES of spray combustion

Ahmad Hadadpour; Shijie Xu; Yan Zhang; Xue Song Bai; Mehdi Jangi

doi:10.1016/j.proci.2022.09.014

An extended FGM model with transported PDF for LES of spray combustion

Ahmad Hadadpour^*, Shijie Xu^*, Yan Zhang, Xue Song Bai, Mehdi Jangi

^*Corresponding author for this work

Mechanical Engineering

Research output: Contribution to journal › Article › peer-review

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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 modeling 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.

Original language	English
Number of pages	10
Journal	Proceedings of the Combustion Institute
Early online date	23 Oct 2022
DOIs	https://doi.org/10.1016/j.proci.2022.09.014
Publication status	E-pub ahead of print - 23 Oct 2022

Bibliographical note

Funding Information:
This work was sponsored by the Swedish Research Council (VR). AH was partially sponsored by Scania CV AB. SX and YZ were partially sponsored by the China Scholarship Council (CSC). The simulations were performed on NSC, HPC2N and PDC provided by the Swedish National Infrastructure for Computing (SNIC).

Keywords

LES
Spray combustion
Flamelet generated manifold (FGM)
Eulerian stochastic fields (ESF)
Reaction progress variable
Engine combustion network (ECN)

ASJC Scopus subject areas

General Chemical Engineering
Mechanical Engineering
Physical and Theoretical Chemistry

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Cite this

@article{51c108f1990b4023aa90351bfa414323,

title = "An extended FGM model with transported PDF for LES of spray combustion",

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 modeling 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.",

keywords = "LES, Spray combustion, Flamelet generated manifold (FGM), Eulerian stochastic fields (ESF), Reaction progress variable, Engine combustion network (ECN)",

author = "Ahmad Hadadpour and Shijie Xu and Yan Zhang and Bai, {Xue Song} and Mehdi Jangi",

note = "Funding Information: This work was sponsored by the Swedish Research Council (VR). AH was partially sponsored by Scania CV AB. SX and YZ were partially sponsored by the China Scholarship Council (CSC). The simulations were performed on NSC, HPC2N and PDC provided by the Swedish National Infrastructure for Computing (SNIC).",

year = "2022",

month = oct,

day = "23",

doi = "10.1016/j.proci.2022.09.014",

language = "English",

journal = "Proceedings of the Combustion Institute",

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TY - JOUR

T1 - An extended FGM model with transported PDF for LES of spray combustion

AU - Hadadpour, Ahmad

AU - Xu, Shijie

AU - Zhang, Yan

AU - Bai, Xue Song

AU - Jangi, Mehdi

N1 - Funding Information: This work was sponsored by the Swedish Research Council (VR). AH was partially sponsored by Scania CV AB. SX and YZ were partially sponsored by the China Scholarship Council (CSC). The simulations were performed on NSC, HPC2N and PDC provided by the Swedish National Infrastructure for Computing (SNIC).

PY - 2022/10/23

Y1 - 2022/10/23

N2 - 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 modeling 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.

AB - 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 modeling 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.

KW - LES

KW - Spray combustion

KW - Flamelet generated manifold (FGM)

KW - Eulerian stochastic fields (ESF)

KW - Reaction progress variable

KW - Engine combustion network (ECN)

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U2 - 10.1016/j.proci.2022.09.014

DO - 10.1016/j.proci.2022.09.014

M3 - Article

AN - SCOPUS:85140843243

SN - 1540-7489

JO - Proceedings of the Combustion Institute

JF - Proceedings of the Combustion Institute

ER -

An extended FGM model with transported PDF for LES of spray combustion

Abstract

Bibliographical note

Keywords

ASJC Scopus subject areas

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