Research output: Contribution in Book/Report/Proceedings - With ISBN/ISSN › Conference contribution/Paper › peer-review
Research output: Contribution in Book/Report/Proceedings - With ISBN/ISSN › Conference contribution/Paper › peer-review
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TY - GEN
T1 - Numerical studies of vortex shedding in forced oscillatory non-premixed flames
AU - Jiang, Xi
PY - 2010
Y1 - 2010
N2 - A comparative study has been performed to investigate the flow instabilities and their interactions in a non-premixed methane jet flame using highly accurate numerical methods. The interaction between the jet flapping modes and buoyancy instability has been examined by comparing a full three-dimensional case and an idealised axisymmetric case, in order to identify the three-dimensional effects on the vortex dynamics. In addition, air co-flow flames have been numerically simulated to investigate the interaction between the shear and buoyancy instabilities. It was found that three-dimensional effects dominate the flame dynamics at downstream locations, where the flame exhibits transitional behaviour. The axisymmetric simulation is only able to capture the flow dynamics close to the jet nozzle exit. The air co-flow tends to stabilise the flame and to reduce the flame unsteadiness, which may also have an impact on the flickering frequency. Three-dimensional effects can greatly affect the strength of flame oscillation energy at downstream location, where the flapping modes enhance the flame unsteadiness. On the contrary, co-flow tends to reduce the strength of flame oscillation, especially at upstream locations.
AB - A comparative study has been performed to investigate the flow instabilities and their interactions in a non-premixed methane jet flame using highly accurate numerical methods. The interaction between the jet flapping modes and buoyancy instability has been examined by comparing a full three-dimensional case and an idealised axisymmetric case, in order to identify the three-dimensional effects on the vortex dynamics. In addition, air co-flow flames have been numerically simulated to investigate the interaction between the shear and buoyancy instabilities. It was found that three-dimensional effects dominate the flame dynamics at downstream locations, where the flame exhibits transitional behaviour. The axisymmetric simulation is only able to capture the flow dynamics close to the jet nozzle exit. The air co-flow tends to stabilise the flame and to reduce the flame unsteadiness, which may also have an impact on the flickering frequency. Three-dimensional effects can greatly affect the strength of flame oscillation energy at downstream location, where the flapping modes enhance the flame unsteadiness. On the contrary, co-flow tends to reduce the strength of flame oscillation, especially at upstream locations.
KW - JET DIFFUSION FLAMES
KW - SIMULATION
KW - DYNAMICS
KW - COMBUSTION
KW - SCHEMES
KW - PLUMES
KW - COFLOW
KW - AIR
U2 - 10.1088/1757-899X/10/1/012030
DO - 10.1088/1757-899X/10/1/012030
M3 - Conference contribution/Paper
SN - *****************
SP - -
BT - 9th World Congress on Computational Mechanics and 4th Asian Pacific Congress on Computational Mechanics
A2 - Khalili, N
A2 - Valliappan, S
A2 - Li, Q
A2 - Russell, A
PB - IOP Publishing Ltd
CY - BRISTOL
ER -