Math. Model. Nat. Phenom.
Volume 13, Number 6, 2018
Mathematical modelling in combustion sciences
|Number of page(s)||16|
|Published online||27 September 2018|
Dynamics of lean premixed flames stabilized on a meso-scale bluff-body in an unconfined flow field
Clean Combustion Research Center, King Abdullah University of Science and Technology (KAUST),
23955-6900, Saudi Arabia
2 School of Mechanical Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Republic of Korea
* Corresponding author: email@example.com
Accepted: 18 July 2018
Two-dimensional direct numerical simulations were conducted to investigate the dynamics of lean premixed flames stabilized on a meso-scale bluff-body in hydrogen-air and syngas-air mixtures. To eliminate the flow confinement effect due to the narrow channel, a larger domain size at twenty times the bluff-body dimension was used in the new simulations. Flame/flow dynamics were examined as the mean inflow velocity is incrementally raised until blow-off occurs. As the mean inflow velocity is increased, several distinct modes in the flame shape and fluctuation patterns were observed. In contrast to our previous study with a narrow channel, the onset of local extinction was observed during the asymmetric vortex shedding mode. Consequently, the flame stabilization and blow-off behavior was found to be dictated by the combined effects of the hot product gas pocket entrained into the extinction zone and the ability to auto-ignite the mixture within the given residence time corresponding to the lateral flame fluctuations. A proper time scale analysis is attempted to characterize the flame blow-off mechanism, which turns out to be consistent with the classic theory of Zukoski and Marble.
Mathematics Subject Classification: 80A25 / 76F65 / 76D05 / 65L06 / 80A32 / 76B47 / 76N15
Key words: Direct numerical simulation / Flame dynamics / Bluff-body stabilization / Premixed flames / Blow-off
© EDP Sciences, 2018
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.