Numerical and experimental analysis of combustion in microchannels with controlled temperature

M.A. Bucci (1) , A. Di Stazio (2) , C. Chauveau (2) , G. Dayma (2) , G. Legros (1) , P. Dagaut (2) , S. Chibbaro (1)

1 DALEMBERT - Institut Jean Le Rond d'Alembert
2 ICARE - Institut de Combustion, Aérothermique, Réactivité et Environnement

This paper reports on joint experimental-numerical investigations of flame dynamics in a microchannel of diameter 1.85 mm. Experiments show that decreasing the diameter of the channel helps the arising of the FREI instability. Yet leaning the mixture is found to be a mean to make the flame more stable. The numerical model used is based on two- dimensional thermo-diffusive equations with one-step chemistry, and it is tested against the experimental results without any calibration. The model turns out to reproduce in a satisfactory manner all the features from a qualitative point of view, and most of them from a quantitative point of view, showing robustness not only with respect to geometry but also to equivalence ratio changes. Nonetheless, while the analysis of frequencies of the FREI instability shows a qualitative agreement, a quantitative discrepancy is unfold. The results suggest that instabilities in microcombustion of CH4/air are fundamentally triggered by hydrodynamics.

Mots clés: numerical modelling; microchannel; microcombustion; flame dynamics

Domaines: Milieux fluides et réactifs

M.A. Bucci, A. Di Stazio, C. Chauveau, G. Dayma, G. Legros, et al.. Numerical and experimental analysis of combustion in microchannels with controlled temperature. Chemical Engineering Science: X, 2019, 4, pp.100034. ⟨10.1016/j.cesx.2019.100034⟩. ⟨hal-02317402⟩