Vassilios Papapostolou
Enstrophy transport conditional on local flow topologies in different regimes of premixed turbulent combustion
Papapostolou, Vassilios; Wacks, Daniel H.; Chakraborty, Nilanjan; Klein, Markus; Im, Hong G.
Authors
Daniel H. Wacks
Nilanjan Chakraborty
Markus Klein
Hong G. Im
Abstract
Enstrophy is an intrinsic feature of turbulent flows, and its transport properties are essential for the understanding of premixed flame-turbulence interaction. The interrelation between the enstrophy transport and flow topologies, which can be assigned to eight categories based on the three invariants of the velocity-gradient tensor, has been analysed here. The enstrophy transport conditional on flow topologies in turbulent premixed flames has been analysed using a Direct Numerical Simulation database representing the corrugated flamelets (CF), thin reaction zones (TRZ) and broken reaction zones (BRZ) combustion regimes. The flame in the CF regime exhibits considerable flame-generated enstrophy, and the dilatation rate and baroclinic torque contributions to the enstrophy transport act as leading order sink and source terms, respectively. Consequently, flow topologies associated with positive dilatation rate values, contribute significantly to the enstrophy transport in the CF regime. By contrast, enstrophy decreases from the unburned to the burned gas side for the cases representing the TRZ and BRZ regimes, with diminishing influences of dilatation rate and baroclinic torque. The enstrophy transport in the TRZ and BRZ regimes is governed by the vortex-stretching and viscous dissipation contributions, similar to non-reacting flows, and topologies existing for all values of dilatation rate remain significant contributors.
Citation
Papapostolou, V., Wacks, D. H., Chakraborty, N., Klein, M., & Im, H. G. (2017). Enstrophy transport conditional on local flow topologies in different regimes of premixed turbulent combustion. Scientific Reports, 7(1), Article 11545. https://doi.org/10.1038/s41598-017-11650-x
| Journal Article Type | Article |
|---|---|
| Acceptance Date | Aug 29, 2017 |
| Online Publication Date | Sep 14, 2017 |
| Publication Date | Sep 14, 2017 |
| Deposit Date | Oct 10, 2017 |
| Publicly Available Date | Oct 10, 2017 |
| Journal | Scientific Reports |
| Electronic ISSN | 2045-2322 |
| Publisher | Nature Research |
| Peer Reviewed | Peer Reviewed |
| Volume | 7 |
| Issue | 1 |
| Article Number | 11545 |
| DOI | https://doi.org/10.1038/s41598-017-11650-x |
| Public URL | https://durham-repository.worktribe.com/output/1343136 |
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