A combination of solid and transverse jet obstacles is proposed to trigger flame acceleration deflagration-to-detonation transition (DDT). numerical study this approach performed by solving the reactive Navier–Stokes equations deploying an adaptive mesh refinement technique. detailed hydrogen–air reaction mechanism with 12 species 42 steps employed. The efficiency mechanisms combined on are inv...

Until now, very few works have been devoted to the predictions of the flame structure resulting from the combustion of a vertical burning wall adjacent to a rectangular pool fire at the floor level. This paper describes the application of a three-dimensional model to the prediction of the aerodynamic field and the thermal structure using a finite volume method for solving the fluid dynamic equa...

Recent experimental investigations of combustion in diesel engines showed that the initial premix burn creates pockets of soot and fuel that must burn out in a diffusion-flame mode in order to complete the combustion [5, 6]. Understanding the final stages of this process is critical to predicting the emissions of soot and NOx. This effort uses numerical simulations to investigate burnout of dif...

The chemical structure of an opposed flow, methane diffusion flame is studied using a chemical kinetic model and the results are compared to experimental measurements. The chemical kinetic paths leading to aromatics and polycyclic aromatics hydrocarbons (PAHs) in the diffusion flame are identified. These paths all involve resonantly stabilized radicals which include propargyl, allyl, cyclopenta...

In this thesis, thermal-diffusive instabilities are studied experimentally in diffusion flames. The novel species injector of a recently developed research burner, consisting of an array of hypodermic needles, which allows to produce quasi one-dimensional unstrained diffusion flames has been improved. It is used in a new symmetric design with fuel and oxidizer injected through needle arrays whi...

Edge flames were investigated in a methane/O2/N2 counterflow diffusion flame burner. In a typical experiment, a stable counterflow diffusion flame in an axysymmetric configuration was perturbed by lowering the relevant Damköhler number slightly below the extinction value, Daext. As a result, the flame extinguished in the vicinity of the burner axis where conditions were uniform. An edge flame e...

The flame born in the deep interior of a white dwarf that becomes a Type Ia supernova is subject to several instabilities, the combination of which determines the observational characteristics of the explosion. We briefly review these instabilities and discuss the length scales for which each dominates. Their cumulative effect is to accelerate the speed of the flame beyond its laminar value, bu...

A turbulent methane–oxygen diffusion flame is studied using a direct numerical simulation setup. The operating regime and turbulence characteristics are chosen to resemble those of modern methane rocket combustor. Local dimensionless numbers defined evaluated, their relationship with the kinetic energy transport budget studied. Positive net generation observed in reaction shear layer. It found ...

The speed of propagation of a premixed turbulent flame correlates with the intensity of the turbulence encountered by the flame. One consequence of this property is that premixed flames in both laboratory experiments and practical combustors require some type of stabilization mechanism to prevent blow-off and flashback. The stabilization devices often introduce a level of geometric complexity t...