Stabilization and liftoff length of a non-premixed methane/air jet flame discharging into a high-temperature environment: An accelerated transported PDF method
(2015) In Combustion and Flame 162(2). p.408-419- Abstract
- A particle-based transported probability density function (PDF) method with a novel chemistry acceleration technique is developed in this work. The technique is based on the chemistry coordinate mapping (CCM) approach that was proposed in our previous works for accelerating direct numerical simulations (DNS) of partially premixed combustion. The method is first validated using Sandia flames D and F. It is shown that PDF-CCM results converge toward those obtained without CCM as phase-space resolution increases. PDF-CCM is then applied to simulate methane/air lifted jet flames in vitiated coflow reported in experiments by Cabra et al. (2005). It is shown that combustion is initiated in the form of auto-ignition in very fuel-lean gases where... (More)
- A particle-based transported probability density function (PDF) method with a novel chemistry acceleration technique is developed in this work. The technique is based on the chemistry coordinate mapping (CCM) approach that was proposed in our previous works for accelerating direct numerical simulations (DNS) of partially premixed combustion. The method is first validated using Sandia flames D and F. It is shown that PDF-CCM results converge toward those obtained without CCM as phase-space resolution increases. PDF-CCM is then applied to simulate methane/air lifted jet flames in vitiated coflow reported in experiments by Cabra et al. (2005). It is shown that combustion is initiated in the form of auto-ignition in very fuel-lean gases where the gas velocity is low (the residence time is long) and the gas temperature is high (the ignition delay time is short). The ignition delay of the mixture below the liftoff position scales well with the liftoff height at different coflow temperature conditions. The combustion process above the liftoff height can develop into different modes depending on the coflow temperature. For high-temperature coflow, a premixed-burned combustion is formed above the liftoff height, which involves fuel-lean to fuel-rich burning modes; a triple-flame structure eventually is formed a few nozzle diameters above the liftoff position. For low-temperature coflow, the ignition delay and the liftoff height are sufficiently large to allow premixing between fuel and oxidizer before the onset of high-temperature combustion; in this case, a lean-to-stoichiometric premixed burn combustion is established downstream of the liftoff height, and no obvious triple-flame structure is formed at this condition. (C) 2014 The Combustion Institute. Published by Elsevier Inc. All rights reserved. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/5201195
- author
- Jangi, Mehdi LU ; Zhao, Xinyu ; Haworth, Dan C. and Bai, Xue-Song LU
- organization
- publishing date
- 2015
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- CCM, Transported PDF, Acceleration technique, Lifted flame
- in
- Combustion and Flame
- volume
- 162
- issue
- 2
- pages
- 408 - 419
- publisher
- Elsevier
- external identifiers
-
- wos:000348411900010
- scopus:84919909191
- ISSN
- 0010-2180
- DOI
- 10.1016/j.combustflame.2014.07.031
- language
- English
- LU publication?
- yes
- id
- 0aa9565a-86dd-4b6c-846e-da5f5f46aa9a (old id 5201195)
- date added to LUP
- 2016-04-01 12:55:18
- date last changed
- 2022-01-27 08:18:14
@article{0aa9565a-86dd-4b6c-846e-da5f5f46aa9a,
abstract = {{A particle-based transported probability density function (PDF) method with a novel chemistry acceleration technique is developed in this work. The technique is based on the chemistry coordinate mapping (CCM) approach that was proposed in our previous works for accelerating direct numerical simulations (DNS) of partially premixed combustion. The method is first validated using Sandia flames D and F. It is shown that PDF-CCM results converge toward those obtained without CCM as phase-space resolution increases. PDF-CCM is then applied to simulate methane/air lifted jet flames in vitiated coflow reported in experiments by Cabra et al. (2005). It is shown that combustion is initiated in the form of auto-ignition in very fuel-lean gases where the gas velocity is low (the residence time is long) and the gas temperature is high (the ignition delay time is short). The ignition delay of the mixture below the liftoff position scales well with the liftoff height at different coflow temperature conditions. The combustion process above the liftoff height can develop into different modes depending on the coflow temperature. For high-temperature coflow, a premixed-burned combustion is formed above the liftoff height, which involves fuel-lean to fuel-rich burning modes; a triple-flame structure eventually is formed a few nozzle diameters above the liftoff position. For low-temperature coflow, the ignition delay and the liftoff height are sufficiently large to allow premixing between fuel and oxidizer before the onset of high-temperature combustion; in this case, a lean-to-stoichiometric premixed burn combustion is established downstream of the liftoff height, and no obvious triple-flame structure is formed at this condition. (C) 2014 The Combustion Institute. Published by Elsevier Inc. All rights reserved.}},
author = {{Jangi, Mehdi and Zhao, Xinyu and Haworth, Dan C. and Bai, Xue-Song}},
issn = {{0010-2180}},
keywords = {{CCM; Transported PDF; Acceleration technique; Lifted flame}},
language = {{eng}},
number = {{2}},
pages = {{408--419}},
publisher = {{Elsevier}},
series = {{Combustion and Flame}},
title = {{Stabilization and liftoff length of a non-premixed methane/air jet flame discharging into a high-temperature environment: An accelerated transported PDF method}},
url = {{http://dx.doi.org/10.1016/j.combustflame.2014.07.031}},
doi = {{10.1016/j.combustflame.2014.07.031}},
volume = {{162}},
year = {{2015}},
}