1 Department of Civil Engineering, Technical University of Denmark2 Section for Building Design, Department of Civil Engineering, Technical University of Denmark3 Princeton University4 Tsinghua University5 Princeton University6 Tsinghua University
The cells that continuously develop over the flame surface of an expanding spherical flame increase its area and thereby the global propagation rate, resulting in the possibility of self-acceleration. The present study examines whether this self-acceleration could be self-similar, and, if so, whether it could also be self-turbulizing. Extensive experiments at elevated pressures and thereby reduced laminar flame thicknesses and enhanced propensity to exhibit Darrieus-Landau instability were conducted for hydrogen/air mixtures over an extensive range of equivalence ratios. The results demonstrate the strong possibility of self-similar flame acceleration, weak influence of the system pressure and diffusional-thermal instability, and a corresponding moderate spread in the power-law acceleration exponent.
Combustion Institute. Proceedings, 2013, Vol 34, Issue 1, p. 937-945