A Numerical Study on Premixed Turbulent Planar Ammonia/Air and Ammonia/Hydrogen/Air Flames : An Analysis on Flame Displacement Speed and Burning Velocity

Parsa Tamadonfar; Shervin Karimkashi; Ossi Kaario; Ville Vuorinen

doi:10.1007/s10494-023-00445-y

A Numerical Study on Premixed Turbulent Planar Ammonia/Air and Ammonia/Hydrogen/Air Flames : An Analysis on Flame Displacement Speed and Burning Velocity

Parsa Tamadonfar^*, Shervin Karimkashi, Ossi Kaario, Ville Vuorinen

^*Corresponding author for this work

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

1 Citation (Scopus)

52 Downloads (Pure)

Abstract

The economic storage and transportation of ammonia (NH ₃), and its capability to be thermally decomposed to hydrogen (H ₂) make it a potential carbon-free synthetic fuel for the future. To comprehend the fundamental characteristics of NH ₃ as a primary fuel enriched with H ₂ under low turbulent premixed flame conditions, three quasi direct numerical simulations (quasi-DNS) with detailed chemistry and the mixture-averaged transport model are conducted under decaying turbulence herein. The Karlovitz number is fixed to 4.28 for all the test conditions. The blending ratio (α), specifying the hydrogen concentration in the ammonia/hydrogen mixture, varies from 0.0 to 0.6. The results reveal that the mean value of the density-weighted flame displacement speed (Sd∗) is similar to (higher than) the unstrained premixed laminar burning velocity (SL0) for NH ₃/ air flame (NH ₃/ H ₂/ air flames). Furthermore, the performance of two extrapolation relations for estimating Sd∗ as linear and non-linear functions of flame front curvature is discussed thoroughly. The performances of both models are almost similar when evaluating the data near the leading edge of the flame. However, the non-linear one offers more accurate results near the trailing edge of the flame. The results show that the mean flame stretch factor increases with increasing the blending ratio, suggesting that the mean flamelet consumption velocity deviates from SL0 by enriching the mixture with H ₂ . The mean value of the local equivalence ratio (ϕ) for the turbulent NH ₃/ air flame is almost equal to its laminar counterpart, while it deviates significantly for NH ₃/ H ₂/ air flames. In addition, the local equivalence ratio for the flame front with positive curvature values is higher than the negatively curved regions for NH ₃/ H ₂/ air flames due to H ₂ preferential diffusion. Furthermore, the results indicate that hydrogen is consumed faster in positively curved regions compared to the negatively curved zones due to enhanced reaction rates of specific chemical reactions.

Original language	English
Pages (from-to)	717-741
Number of pages	25
Journal	Flow Turbulence and Combustion
Volume	111
Issue number	2
DOIs	https://doi.org/10.1007/s10494-023-00445-y
Publication status	Published - Aug 2023
MoE publication type	A1 Journal article-refereed

Keywords

Ammonia/hydrogen/air flames
Diffusion flux
Flame displacement speed
Local equivalence ratio
Premixed turbulent flames
Quasi direct numerical simulation

Access to Document

10.1007/s10494-023-00445-yLicence: CC BY

s10494-023-00445-yFinal published version, 2.51 MBLicence: CC BY

Cite this

@article{434f140aba4748cda205ddefc6d8c33e,

title = "A Numerical Study on Premixed Turbulent Planar Ammonia/Air and Ammonia/Hydrogen/Air Flames : An Analysis on Flame Displacement Speed and Burning Velocity",

abstract = "The economic storage and transportation of ammonia (NH 3), and its capability to be thermally decomposed to hydrogen (H 2) make it a potential carbon-free synthetic fuel for the future. To comprehend the fundamental characteristics of NH 3 as a primary fuel enriched with H 2 under low turbulent premixed flame conditions, three quasi direct numerical simulations (quasi-DNS) with detailed chemistry and the mixture-averaged transport model are conducted under decaying turbulence herein. The Karlovitz number is fixed to 4.28 for all the test conditions. The blending ratio (α), specifying the hydrogen concentration in the ammonia/hydrogen mixture, varies from 0.0 to 0.6. The results reveal that the mean value of the density-weighted flame displacement speed (Sd∗) is similar to (higher than) the unstrained premixed laminar burning velocity (SL0) for NH 3/ air flame (NH 3/ H 2/ air flames). Furthermore, the performance of two extrapolation relations for estimating Sd∗ as linear and non-linear functions of flame front curvature is discussed thoroughly. The performances of both models are almost similar when evaluating the data near the leading edge of the flame. However, the non-linear one offers more accurate results near the trailing edge of the flame. The results show that the mean flame stretch factor increases with increasing the blending ratio, suggesting that the mean flamelet consumption velocity deviates from SL0 by enriching the mixture with H 2 . The mean value of the local equivalence ratio (ϕ) for the turbulent NH 3/ air flame is almost equal to its laminar counterpart, while it deviates significantly for NH 3/ H 2/ air flames. In addition, the local equivalence ratio for the flame front with positive curvature values is higher than the negatively curved regions for NH 3/ H 2/ air flames due to H 2 preferential diffusion. Furthermore, the results indicate that hydrogen is consumed faster in positively curved regions compared to the negatively curved zones due to enhanced reaction rates of specific chemical reactions.",

keywords = "Ammonia/hydrogen/air flames, Diffusion flux, Flame displacement speed, Local equivalence ratio, Premixed turbulent flames, Quasi direct numerical simulation",

author = "Parsa Tamadonfar and Shervin Karimkashi and Ossi Kaario and Ville Vuorinen",

note = "Funding Information: Open Access funding provided by Aalto University. The present study has been financially supported by the Academy of Finland [grant numbers 318024, 332835, and 332784]. Funding Information: The present study has been financially supported by the Academy of Finland [grant numbers 318024, 332835, and 332784]. The authors would like to thank CSC (Finnish IT Center for Science) for providing the computational resources. Funding Information: The present study has been financially supported by the Academy of Finland [grant numbers 318024, 332835, and 332784]. The authors would like to thank CSC (Finnish IT Center for Science) for providing the computational resources. Publisher Copyright: {\textcopyright} 2023, The Author(s).",

year = "2023",

month = aug,

doi = "10.1007/s10494-023-00445-y",

language = "English",

volume = "111",

pages = "717--741",

journal = "Flow Turbulence and Combustion",

issn = "1386-6184",

publisher = "Springer",

number = "2",

}

A Numerical Study on Premixed Turbulent Planar Ammonia/Air and Ammonia/Hydrogen/Air Flames : An Analysis on Flame Displacement Speed and Burning Velocity. / Tamadonfar, Parsa ; Karimkashi, Shervin ; Kaario, Ossi et al.
In: Flow Turbulence and Combustion, Vol. 111, No. 2, 08.2023, p. 717-741.

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

TY - JOUR

T1 - A Numerical Study on Premixed Turbulent Planar Ammonia/Air and Ammonia/Hydrogen/Air Flames : An Analysis on Flame Displacement Speed and Burning Velocity

AU - Tamadonfar, Parsa

AU - Karimkashi, Shervin

AU - Kaario, Ossi

AU - Vuorinen, Ville

N1 - Funding Information: Open Access funding provided by Aalto University. The present study has been financially supported by the Academy of Finland [grant numbers 318024, 332835, and 332784]. Funding Information: The present study has been financially supported by the Academy of Finland [grant numbers 318024, 332835, and 332784]. The authors would like to thank CSC (Finnish IT Center for Science) for providing the computational resources. Funding Information: The present study has been financially supported by the Academy of Finland [grant numbers 318024, 332835, and 332784]. The authors would like to thank CSC (Finnish IT Center for Science) for providing the computational resources. Publisher Copyright: © 2023, The Author(s).

PY - 2023/8

Y1 - 2023/8

N2 - The economic storage and transportation of ammonia (NH 3), and its capability to be thermally decomposed to hydrogen (H 2) make it a potential carbon-free synthetic fuel for the future. To comprehend the fundamental characteristics of NH 3 as a primary fuel enriched with H 2 under low turbulent premixed flame conditions, three quasi direct numerical simulations (quasi-DNS) with detailed chemistry and the mixture-averaged transport model are conducted under decaying turbulence herein. The Karlovitz number is fixed to 4.28 for all the test conditions. The blending ratio (α), specifying the hydrogen concentration in the ammonia/hydrogen mixture, varies from 0.0 to 0.6. The results reveal that the mean value of the density-weighted flame displacement speed (Sd∗) is similar to (higher than) the unstrained premixed laminar burning velocity (SL0) for NH 3/ air flame (NH 3/ H 2/ air flames). Furthermore, the performance of two extrapolation relations for estimating Sd∗ as linear and non-linear functions of flame front curvature is discussed thoroughly. The performances of both models are almost similar when evaluating the data near the leading edge of the flame. However, the non-linear one offers more accurate results near the trailing edge of the flame. The results show that the mean flame stretch factor increases with increasing the blending ratio, suggesting that the mean flamelet consumption velocity deviates from SL0 by enriching the mixture with H 2 . The mean value of the local equivalence ratio (ϕ) for the turbulent NH 3/ air flame is almost equal to its laminar counterpart, while it deviates significantly for NH 3/ H 2/ air flames. In addition, the local equivalence ratio for the flame front with positive curvature values is higher than the negatively curved regions for NH 3/ H 2/ air flames due to H 2 preferential diffusion. Furthermore, the results indicate that hydrogen is consumed faster in positively curved regions compared to the negatively curved zones due to enhanced reaction rates of specific chemical reactions.

AB - The economic storage and transportation of ammonia (NH 3), and its capability to be thermally decomposed to hydrogen (H 2) make it a potential carbon-free synthetic fuel for the future. To comprehend the fundamental characteristics of NH 3 as a primary fuel enriched with H 2 under low turbulent premixed flame conditions, three quasi direct numerical simulations (quasi-DNS) with detailed chemistry and the mixture-averaged transport model are conducted under decaying turbulence herein. The Karlovitz number is fixed to 4.28 for all the test conditions. The blending ratio (α), specifying the hydrogen concentration in the ammonia/hydrogen mixture, varies from 0.0 to 0.6. The results reveal that the mean value of the density-weighted flame displacement speed (Sd∗) is similar to (higher than) the unstrained premixed laminar burning velocity (SL0) for NH 3/ air flame (NH 3/ H 2/ air flames). Furthermore, the performance of two extrapolation relations for estimating Sd∗ as linear and non-linear functions of flame front curvature is discussed thoroughly. The performances of both models are almost similar when evaluating the data near the leading edge of the flame. However, the non-linear one offers more accurate results near the trailing edge of the flame. The results show that the mean flame stretch factor increases with increasing the blending ratio, suggesting that the mean flamelet consumption velocity deviates from SL0 by enriching the mixture with H 2 . The mean value of the local equivalence ratio (ϕ) for the turbulent NH 3/ air flame is almost equal to its laminar counterpart, while it deviates significantly for NH 3/ H 2/ air flames. In addition, the local equivalence ratio for the flame front with positive curvature values is higher than the negatively curved regions for NH 3/ H 2/ air flames due to H 2 preferential diffusion. Furthermore, the results indicate that hydrogen is consumed faster in positively curved regions compared to the negatively curved zones due to enhanced reaction rates of specific chemical reactions.

KW - Ammonia/hydrogen/air flames

KW - Diffusion flux

KW - Flame displacement speed

KW - Local equivalence ratio

KW - Premixed turbulent flames

KW - Quasi direct numerical simulation

UR - http://www.scopus.com/inward/record.url?scp=85164518017&partnerID=8YFLogxK

UR - https://doi.org/10.1007/s10494-023-00513-3

U2 - 10.1007/s10494-023-00445-y

DO - 10.1007/s10494-023-00445-y

M3 - Article

AN - SCOPUS:85164518017

SN - 1386-6184

VL - 111

SP - 717

EP - 741

JO - Flow Turbulence and Combustion

JF - Flow Turbulence and Combustion

IS - 2

ER -

A Numerical Study on Premixed Turbulent Planar Ammonia/Air and Ammonia/Hydrogen/Air Flames : An Analysis on Flame Displacement Speed and Burning Velocity

Abstract

Keywords

Access to Document

Other files and links

Fingerprint

Cool/Kaario: Reacting flow near cool walls

DIAG/Karimkashi: Multi-fuel combustion: development of a diagnostic tool for carbon-neutral combustion

Tri-Reactivity Ignition: Simulation and Experiments

Cite this

A Numerical Study on Premixed Turbulent Planar Ammonia/Air and Ammonia/Hydrogen/Air Flames : An Analysis on Flame Displacement Speed and Burning Velocity

Abstract

Keywords

Access to Document

Other files and links

Fingerprint

Projects

Cool/Kaario: Reacting flow near cool walls

DIAG/Karimkashi: Multi-fuel combustion: development of a diagnostic tool for carbon-neutral combustion

Tri-Reactivity Ignition: Simulation and Experiments

Cite this