Ignition and deflagration-to-detonation transition modes in ethylene/air mixtures behind a reflected shock
نویسندگان
چکیده
Dynamics of ethylene autoignition and deflagration-to-detonation transition (DDT) are first numerically investigated in a one-dimensional shock tube using reduced chemistry including 10 species reactions. Different combustion modes through considering various premixed gas equivalence ratios (0.2 [Formula: see text] 2.0) incident wave Mach numbers (1.8[Formula: text]3.2). Four ignition DDT observed from the studied cases, i.e., no ignition, deflagration combustion, detonation after reflected shock, behind shock. For development three hot spots formed. The one occurs at wall surface re-compression contact surface, which further develops to reaction because “the explosion explosion” regime. other two off wall, respectively, caused by shock/rarefaction interaction induction compressed mixture. last spot couples with process, eventually leads combustion. interactions, as well its qualitatively similar mode reflection, before collision point. However, only is induced collision, also but cannot catch up compression whereas reflection. chemical timescale increases shock/contact decreases shocks, interaction. Therefore, mixture reactivity weakened intensified rarefaction wave. multi-dimensionality characteristics, shock/boundary layer bifurcation, destabilization, detonation, present two-dimensional configuration. Planar formed central region due wave/reflected left right bifurcations separation boundary then sequentially ignited.
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ژورنال
عنوان ژورنال: Physics of Fluids
سال: 2022
ISSN: ['1527-2435', '1089-7666', '1070-6631']
DOI: https://doi.org/10.1063/5.0103013