One of the well-known properties of turbulent, premixed flames is that their speed of propagtion is correlated to the intensity of the turbulence they encounter. A simple consequence is that these types of flames are inherently unstable. Given a source of turbulence, if the flame is propagating faster than the mean flow, it will drift upstream and encounter increased turbulent intensities that ...

diffusion flame in a dust cloud combustion in a counterflow configuration is investigated in this research. it is presumed that the fuel particles vaporize first to yield a gaseous fuel to oxidize with the gas phase. the reaction rate is assumed to be of the arrhenius type. conservation equations for the non-unity lewis number are solved and the flame temperature with the variations of differen...

The purpose of this study was to compare the effect of casting temperature and atmosphere on the castability of three Ni-Cr alloys against direct flame casting method. Vera Bond (VB), Vera Bond 2 (VB2) and Wiron 99 (W99) were cast at three temperatures: VB and VB2 (1310 °C, 1340 °C and 1370 °C); W99 (1400 °C, 1430 °C and 1460 °C) in atmosphere, vacuum and direct flame. Each alloy was cast in se...

This report describes an approach to the parallelisation of agent-based applications. The software framework which forms the foundation of this work is the Flexible Large-scale Agent Modelling Environment FLAME which is being developed in a collaboration between the Computer Science Department of the University of Sheffield and the Software Engineering Group at STFC’s Rutherford Appleton Labora...

We analyze the local flame extinction and reignition of a counterflow diffusion flame perturbed by a laminar vortex ring. Local flame extinction leads to the appearance of flame edges separating the burning and extinguished regions of the distorted mixing layer. The dynamics of these edges is modeled based on previous numerical results, with heat release effects fully taken into account, which ...

The interaction of a vortex pair with a premixed flame serves as an important prototype for premixed turbulent combustion. In this study, we investigate the interaction of a counterrotating vortex pair with an initially flat premixed methane flame. We focus on characterizing the mechanical nature of the flame-vortex interaction and on the features of the interaction strongly affected by fuel eq...

A key outstanding issue with turbulent premixed flames lies in modeling the burning rate which may be related to the flame surface density if the laminar flamelet assumption applies. Although it is generally accepted that, in the flamelet regimes, higher turbulence levels increases flame wrinkling and hence its surface density, recent imaging experiments are not consistent making this a controv...

An HPLC-UV/MS method has been developed to identify and quantify flame retardants in post-consumer plastics from waste of electric and electronic equipment (WEEE). Atmospheric pressure chemical ionisation spectra of 15 brominated and phosphate-based flame retardants were recorded and interpreted. The method was applied to detect flame retardant additives in polymer extracts obtained from pressu...

Gas-phase transient effects during the combustion of an infinite linear array of droplets are studied in the limit of infinite Damköler number and in the absence of surrounding convective effects. The present study stems from the quantification of truncation-distance effects on the droplet mass vaporization rate, flame position and flame shape in quasisteady numerical simulations. The solution ...

The lagrangian point of view is adopted to study turbulent premixed combustion. The evolution of the volume fraction of combustion products is established by the Reynolds transport theorem. It emerges that the burned-mass fraction is led by the turbulent particle motion, by the flame front velocity, and by the mean curvature of the flame front. A physical requirement connecting particle turbule...