Flame-turbulence interactions during flame acceleration using solid and fluid obstacles
Flame-turbulence interactions during flame acceleration using solid and fluid obstacles
A combination of solid and transverse jet obstacles is proposed to trigger flame acceleration and deflagration-to-detonation transition (DDT). A numerical study of this approach is performed by solving the reactive Navier-Stokes equations deploying an adaptive mesh refinement technique. A detailed hydrogen-air reaction mechanism with 12 species and 42 steps is employed. The efficiency and mechanisms of the combined obstacles on the flame acceleration are investigated comprehensively. The effects of multiple jets, jet start time, and jet stagnation pressure on the DDT process are studied. Results show that there is a 22.26% improvement in the DDT run-up time and a 33.36% reduction in the DDT run-up distance for the combined obstacles compared to that having only solid obstacles. The jet acts as an obstruction by producing a suitable blockage ratio and introducing an intense turbulent region due to the Kelvin-Helmholtz instability. This leads to dramatic flame-turbulence interactions, increasing the flame surface area dramatically. The dual jet produces mushroom-like vortices, leading to a significantly stretched flame front and intensive Kelvin-Helmholtz instabilities, and therefore, these features produce a high flame acceleration. As the jet operation time decreases, the jet obstacle almost changes its role from both physical blockage ratio and turbulence and vorticity generator to a physical blockage ratio. There is a moderate jet stagnation pressure that reduces the run-up time to detonation and run-up distance to detonation in the obstacle-laden chamber. While further increasing the jet stagnation pressure, it does not have a positive effect on shortening the detonation transition.
Flame acceleration, Kelvin-Helmholtz (K-H) instability, deflagration-to-detonation transition (DDT), flame-turbulence interaction, transverse jet
Zhao, Wandong
d9c8a7b9-8e16-4e9e-9c18-d5ee83d1d979
Liang, Jianhan
fd8229b7-c7f4-4a1b-b94f-abce393f9e9a
Deiterding, Ralf
ce02244b-6651-47e3-8325-2c0a0c9c6314
Cai, Xiaodong
293bf621-f0e1-48ba-abaa-b41da81ea244
Wang, Xinxin
faafb881-5948-40d5-b2bb-df56f6687c32
13 October 2022
Zhao, Wandong
d9c8a7b9-8e16-4e9e-9c18-d5ee83d1d979
Liang, Jianhan
fd8229b7-c7f4-4a1b-b94f-abce393f9e9a
Deiterding, Ralf
ce02244b-6651-47e3-8325-2c0a0c9c6314
Cai, Xiaodong
293bf621-f0e1-48ba-abaa-b41da81ea244
Wang, Xinxin
faafb881-5948-40d5-b2bb-df56f6687c32
Zhao, Wandong, Liang, Jianhan, Deiterding, Ralf, Cai, Xiaodong and Wang, Xinxin
(2022)
Flame-turbulence interactions during flame acceleration using solid and fluid obstacles.
Physics of Fluids, 34 (10), [106106].
(doi:10.1063/5.0118091).
Abstract
A combination of solid and transverse jet obstacles is proposed to trigger flame acceleration and deflagration-to-detonation transition (DDT). A numerical study of this approach is performed by solving the reactive Navier-Stokes equations deploying an adaptive mesh refinement technique. A detailed hydrogen-air reaction mechanism with 12 species and 42 steps is employed. The efficiency and mechanisms of the combined obstacles on the flame acceleration are investigated comprehensively. The effects of multiple jets, jet start time, and jet stagnation pressure on the DDT process are studied. Results show that there is a 22.26% improvement in the DDT run-up time and a 33.36% reduction in the DDT run-up distance for the combined obstacles compared to that having only solid obstacles. The jet acts as an obstruction by producing a suitable blockage ratio and introducing an intense turbulent region due to the Kelvin-Helmholtz instability. This leads to dramatic flame-turbulence interactions, increasing the flame surface area dramatically. The dual jet produces mushroom-like vortices, leading to a significantly stretched flame front and intensive Kelvin-Helmholtz instabilities, and therefore, these features produce a high flame acceleration. As the jet operation time decreases, the jet obstacle almost changes its role from both physical blockage ratio and turbulence and vorticity generator to a physical blockage ratio. There is a moderate jet stagnation pressure that reduces the run-up time to detonation and run-up distance to detonation in the obstacle-laden chamber. While further increasing the jet stagnation pressure, it does not have a positive effect on shortening the detonation transition.
Text
Flame-turbulence interactions-3-R1-1-RD
- Accepted Manuscript
Text
5.0118091
- Version of Record
Available under License Other.
More information
Accepted/In Press date: 11 September 2022
e-pub ahead of print date: 13 October 2022
Published date: 13 October 2022
Additional Information:
Funding Information:
This work was supported by the National Natural Science Foundation of China (Grant Nos. 11925207 and 91741205) and the China Scholarship Council (Grant No. 202106110005).
Publisher Copyright:
© 2022 Author(s).
Keywords:
Flame acceleration, Kelvin-Helmholtz (K-H) instability, deflagration-to-detonation transition (DDT), flame-turbulence interaction, transverse jet
Identifiers
Local EPrints ID: 471523
URI: http://eprints.soton.ac.uk/id/eprint/471523
ISSN: 1070-6631
PURE UUID: d43a2f64-d2d3-4a53-80fe-bd1e49747a2d
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Date deposited: 10 Nov 2022 17:31
Last modified: 17 Mar 2024 07:33
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Contributors
Author:
Wandong Zhao
Author:
Jianhan Liang
Author:
Xiaodong Cai
Author:
Xinxin Wang
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