Said Taileb

Aix-Marseille Université | AMU · Laboratoire de Mécanique, Modélisation & Procédés Propres M2P2 (UMR 6181)

The collision of two subsonic auto-ignition fronts with initial constant velocity was found to transit to detonation only when the collision angle was acute. The interaction of the reactive phase wave with inert hot layers constituted a singularity providing a continuous source of vorticity due to barocline effect. For an acute angle, this singular...

We propose a new single-step mechanism for the combustion of arbitrary hydrocarbons and alcohols. Unlike most single-step models, no tabulation is required, as the method builds upon a new analytical description of the thermo-chemical equilibrium of fuel-oxidizer mixtures including dihydrogen and carbon monoxide-two species usually discarded in one...

This numerical study deals with the hazardous ignition of a jet flame in a vitiated co-flow. A novel formulation, based on a passive scalar variable, will be presented to predict hydrogen auto-ignition events. The model, derived from the theoretical analysis of the Jacobian, correctly describes the appearance and absence of auto-ignition in complex...

This chapter provides an overview of H2 ignition and safety-related ques- tions, to be addressed in the development of future H2 thermal engines. Basics of H2 ignition phenomena are covered in the first part, including the well-known branched- chain oxidation reactions described by Semenov & Hinshelwood, as well as useful analytical derivations of...

The propagation of multidimensional gaseous detonations at elevated pressures was investigated numerically. Initial conditions at which deviations from ideal gas are expected (i.e., p0 > 2 MPa) were used to assess whether real gas effects influence their multi-cellular structure. The simplest equation of state that accounts for real gas effects was...

La présente étude s’inscrit dans le cadre général des simulations numériques des détonations dans des conditions non-idéales. Les configurations abordées correspondent à des écoulements rencontrés dans les accidents industriels ainsi que dans les moteurs à détonation rotative, dans lequel le combustible est injecté à des pressions élevées dans un m...

In this paper, computations of gaseous detonations in several configurations are performed and discussed. The objective is to investigate the detonation characteristics, specially the influence of losses, through a quantitative analysis of the mean hydrodynamic structure. The results are divided into two parts: The first one relates to the propagat...

The effect of chemistry modeling on the flow structure and quenching limits of detonations propagating into reactive layers bounded by an inert gas is investigated numerically. Three different kinetic schemes of increasing complexity are used to model a stoichiometric H 2-O 2 mixture: single-step, three-step chain-branching and detailed chemistry....

The effect of chemistry modeling on the flow structure and quenching limits of detonations propagating into reactive layers bounded by an inert gas is investigated numerically. Three different kinetic schemes of increasing complexity are used to model a stoichiometric H2-O2 mixture: single-step, three-step chain-branching and detailed chemistry. Re...

Two-dimensional inviscid simulations are conducted to assess the effect of chemistry modeling on the detonation structure and quenching dynamics of detonations propagating into a semiconfined medium. Two different simplified kinetic schemes are used to model the chemistry of stoichiometric H 2-O 2 mixtures: single-step and three-step chain-branchin...

The multidimensional structure of mildly unstable detonations are examined by numerical computations. These phenomenon have grown in interest since the development of propulsion devices such as pulsed and rotating detonation engines. Rectangular, diagonal and spinning modes are observed in a near-limit propagation detonation. High-order numerical i...