Tangential stretching rate (TSR) analysis of non premixed reactive flows

Type
Article

Authors
Valorani, Mauro
Ciottoli, Pietro Paolo
Galassi, Riccardo Malpica

Online Publication Date
2016-10-16

Print Publication Date
2017

Date
2016-10-16

Abstract
We discuss how the Tangential stretching rate (TSR) analysis, originally developed and tested for spatially homogeneous systems (batch reactors), is extended to spatially non homogeneous systems. To illustrate the effectiveness of the TSR diagnostics, we study the ignition transient in a non premixed, reaction–diffusion model in the mixture fraction space, whose dependent variables are temperature and mixture composition. The reactive mixture considered is syngas/air. A detailed H2/CO mechanism with 12 species and 33 chemical reactions is employed. We will discuss two cases, one involving only kinetics as a model of front propagation purely driven by spontaneous ignition, the other as a model of deflagration wave involving kinetics/diffusion coupling. We explore different aspects of the system dynamics such as the relative role of diffusion and kinetics, the evolution of kinetic eigenvalues, and of the tangential stretching rates computed by accounting for the combined action of diffusion and kinetics as well for kinetics only. We propose criteria based on the TSR concept which allow to identify the most ignitable conditions and to discriminate between spontaneous ignition and deflagration front.

Citation
Valorani M, Ciottoli PP, Galassi RM (2017) Tangential stretching rate (TSR) analysis of non premixed reactive flows. Proceedings of the Combustion Institute 36: 1357–1367. Available: http://dx.doi.org/10.1016/j.proci.2016.09.008.

Acknowledgements
This work was support was CCRC/KAUST 1975--03 CCF Subaward Agreement.

Publisher
Elsevier BV

Journal
Proceedings of the Combustion Institute

DOI
10.1016/j.proci.2016.09.008

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