LES – DFSD modelling of vented hydrogen explosions in a small-scale combustion chamber

Accidental explosions are a plausible danger to the chemical process industries. In the event of a gas explosion, any obstacles placed within the path of the flame generate turbulence, which accelerates the transient flame and raises explosion overpressure, posing a safety hazard. This paper present...

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Main Authors:	Mohamed Elshimy, Salah Ibrahim, Weeratunge Malalasekera
Format:	Default Article
Published:	2021
Subjects:	Computational fluid dynamics Large eddy simulation Hydrogen combustion Dynamic flame surface density Area blockage ratio Process industries
Online Access:	https://hdl.handle.net/2134/14811627.v1
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id	rr-article-14811627
record_format	Figshare
spelling	rr-article-148116272021-06-16T00:00:00Z LES – DFSD modelling of vented hydrogen explosions in a small-scale combustion chamber Mohamed Elshimy (5804771) Salah Ibrahim (1250199) Weeratunge Malalasekera (1258755) Computational fluid dynamics Large eddy simulation Hydrogen combustion Dynamic flame surface density Area blockage ratio Process industries Accidental explosions are a plausible danger to the chemical process industries. In the event of a gas explosion, any obstacles placed within the path of the flame generate turbulence, which accelerates the transient flame and raises explosion overpressure, posing a safety hazard. This paper presents numerical studies using an in-house computational fluid dynamics (CFD) model for lean premixed hydrogen/air flame propagations with an equivalence ratio of 0.7. A laboratory-scale combustion chamber is used with repeated solid obstacles. The transient compressible large eddy simulation (LES) modelling technique combined with a dynamic flame surface density (DFSD) combustion model is used to carry out the numerical simulations in three-dimensional space. The study presented uses eight different baffle configurations with two solid obstructions, which have area blockage ratios of 0.24 and 0.5. The flame speed, maximum rate of pressure-rise as well as peak overpressure magnitude and timing are presented and discussed. Numerical results are validated against available published experimental data. It is concluded that, increasing the solid obstacle area blockage ratio and the number of consecutive baffles results in a raised maximum rate of pressure rise, higher peak explosion overpressure and faster flame propagation. Future model development would require more experimental data, probably in a more congested configuration. 2021-06-16T00:00:00Z Text Journal contribution 2134/14811627.v1 https://figshare.com/articles/journal_contribution/LES_DFSD_modelling_of_vented_hydrogen_explosions_in_a_small-scale_combustion_chamber/14811627 CC BY-NC-ND 4.0
institution	Loughborough University
collection	Figshare
topic	Computational fluid dynamics Large eddy simulation Hydrogen combustion Dynamic flame surface density Area blockage ratio Process industries
spellingShingle	Computational fluid dynamics Large eddy simulation Hydrogen combustion Dynamic flame surface density Area blockage ratio Process industries Mohamed Elshimy Salah Ibrahim Weeratunge Malalasekera LES – DFSD modelling of vented hydrogen explosions in a small-scale combustion chamber
description	Accidental explosions are a plausible danger to the chemical process industries. In the event of a gas explosion, any obstacles placed within the path of the flame generate turbulence, which accelerates the transient flame and raises explosion overpressure, posing a safety hazard. This paper presents numerical studies using an in-house computational fluid dynamics (CFD) model for lean premixed hydrogen/air flame propagations with an equivalence ratio of 0.7. A laboratory-scale combustion chamber is used with repeated solid obstacles. The transient compressible large eddy simulation (LES) modelling technique combined with a dynamic flame surface density (DFSD) combustion model is used to carry out the numerical simulations in three-dimensional space. The study presented uses eight different baffle configurations with two solid obstructions, which have area blockage ratios of 0.24 and 0.5. The flame speed, maximum rate of pressure-rise as well as peak overpressure magnitude and timing are presented and discussed. Numerical results are validated against available published experimental data. It is concluded that, increasing the solid obstacle area blockage ratio and the number of consecutive baffles results in a raised maximum rate of pressure rise, higher peak explosion overpressure and faster flame propagation. Future model development would require more experimental data, probably in a more congested configuration.
format	Default Article
author	Mohamed Elshimy Salah Ibrahim Weeratunge Malalasekera
author_facet	Mohamed Elshimy Salah Ibrahim Weeratunge Malalasekera
author_sort	Mohamed Elshimy (5804771)
title	LES – DFSD modelling of vented hydrogen explosions in a small-scale combustion chamber
title_short	LES – DFSD modelling of vented hydrogen explosions in a small-scale combustion chamber
title_full	LES – DFSD modelling of vented hydrogen explosions in a small-scale combustion chamber
title_fullStr	LES – DFSD modelling of vented hydrogen explosions in a small-scale combustion chamber
title_full_unstemmed	LES – DFSD modelling of vented hydrogen explosions in a small-scale combustion chamber
title_sort	les – dfsd modelling of vented hydrogen explosions in a small-scale combustion chamber
publishDate	2021
url	https://hdl.handle.net/2134/14811627.v1
_version_	1797367990577004544

LES – DFSD modelling of vented hydrogen explosions in a small-scale combustion chamber

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