The University of Southampton
University of Southampton Institutional Repository

Mechanism of end-gas autoignition induced by flame-pressure interactions in confined space

Mechanism of end-gas autoignition induced by flame-pressure interactions in confined space
Mechanism of end-gas autoignition induced by flame-pressure interactions in confined space
The main objective of this work is to comprehensively provide a fundamental understanding of the entire process of the flame-pressure wave interactions with end-gas autoignition and detonation development in a confined chamber by two-dimensional numerical simulations with a stoichiometric hydrogen/air mixture. The flame dynamics, pressure wave propagation, and its structure evolution, together with the mechanism of autoignition and detonation development in the end gas, are analyzed in detail. Six stages, including spherical flame, finger flame, flame with its skirt touching the sidewalls, flame-pressure wave interactions, end-gas autoignition induced by the flame-pressure wave interactions, and detonation development, are observed for the flame development in the confined space. The results demonstrate that the flame-pressure wave multi-interactions result in violent oscillations of the flame shape and speed. Three stages of flame shape evolution during each interaction, backward propagation of the flame front, stretch of the flame front at the boundary layer, and formation of the tulip flame, are captured. A new mechanism in terms of combined effects of the viscous boundary layer and pressure waves is provided for the formation of the tulip flame. It is also found that the velocity distributions in the boundary layer show the trend of increase first and then decrease after the pressure waves pass the fields twice in the opposite directions. The autoignition occurrence and detonation initiation at different positions and different moments in the end-gas region are analyzed. It is indicated that the nonuniform temperature distribution induced by the reflections of pressure waves and the specific pressure wave structures can be responsible for this phenomenon.
1070-6631
1-15
Wei, Haiqiao
357376b6-ab52-4a4c-a4e3-f4d6be35abbd
Zhang, Xiaojun
aed8849c-3c3a-40ae-b579-f984fa369e8b
Zeng, Hao
25483189-e7eb-45e7-8714-f86caf694bc4
Deiterding, Ralf
ce02244b-6651-47e3-8325-2c0a0c9c6314
Pan, Jiaying
164b5178-2f86-433d-a990-e2dd8de39d86
Zhou, Lei
29311185-e1e4-417f-9fb9-ddc1d3f16d09
Wei, Haiqiao
357376b6-ab52-4a4c-a4e3-f4d6be35abbd
Zhang, Xiaojun
aed8849c-3c3a-40ae-b579-f984fa369e8b
Zeng, Hao
25483189-e7eb-45e7-8714-f86caf694bc4
Deiterding, Ralf
ce02244b-6651-47e3-8325-2c0a0c9c6314
Pan, Jiaying
164b5178-2f86-433d-a990-e2dd8de39d86
Zhou, Lei
29311185-e1e4-417f-9fb9-ddc1d3f16d09

Wei, Haiqiao, Zhang, Xiaojun, Zeng, Hao, Deiterding, Ralf, Pan, Jiaying and Zhou, Lei (2019) Mechanism of end-gas autoignition induced by flame-pressure interactions in confined space. Physics of Fluids, 31 (7), 1-15, [076106]. (doi:10.1063/1.5099456).

Record type: Article

Abstract

The main objective of this work is to comprehensively provide a fundamental understanding of the entire process of the flame-pressure wave interactions with end-gas autoignition and detonation development in a confined chamber by two-dimensional numerical simulations with a stoichiometric hydrogen/air mixture. The flame dynamics, pressure wave propagation, and its structure evolution, together with the mechanism of autoignition and detonation development in the end gas, are analyzed in detail. Six stages, including spherical flame, finger flame, flame with its skirt touching the sidewalls, flame-pressure wave interactions, end-gas autoignition induced by the flame-pressure wave interactions, and detonation development, are observed for the flame development in the confined space. The results demonstrate that the flame-pressure wave multi-interactions result in violent oscillations of the flame shape and speed. Three stages of flame shape evolution during each interaction, backward propagation of the flame front, stretch of the flame front at the boundary layer, and formation of the tulip flame, are captured. A new mechanism in terms of combined effects of the viscous boundary layer and pressure waves is provided for the formation of the tulip flame. It is also found that the velocity distributions in the boundary layer show the trend of increase first and then decrease after the pressure waves pass the fields twice in the opposite directions. The autoignition occurrence and detonation initiation at different positions and different moments in the end-gas region are analyzed. It is indicated that the nonuniform temperature distribution induced by the reflections of pressure waves and the specific pressure wave structures can be responsible for this phenomenon.

Text
Flame-pressure wave interactions - final - Accepted Manuscript
Download (22MB)
Text
1.5099456 - Version of Record
Available under License Other.
Download (9MB)

More information

Accepted/In Press date: 30 June 2019
e-pub ahead of print date: 24 July 2019
Published date: 25 July 2019

Identifiers

Local EPrints ID: 433345
URI: http://eprints.soton.ac.uk/id/eprint/433345
ISSN: 1070-6631
PURE UUID: da2f7ae5-223e-48e9-991b-25724660edcf
ORCID for Ralf Deiterding: ORCID iD orcid.org/0000-0003-4776-8183

Catalogue record

Date deposited: 14 Aug 2019 16:30
Last modified: 16 Mar 2024 08:06

Export record

Altmetrics

Contributors

Author: Haiqiao Wei
Author: Xiaojun Zhang
Author: Hao Zeng
Author: Ralf Deiterding ORCID iD
Author: Jiaying Pan
Author: Lei Zhou

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×