In experiments of hot surface ignition and subsequent flame propagation, a puffing flame instability is observed in mixtures that are stagnant and premixed prior to ignition. By varying the size of the hot surface, power input, and combustion vessel volume, it was determined that the instability is a function of the interaction of the flame, with the fluid flow induced by the combustion product...

Flame spreading is a very important phenomenon in the hazard assessment for fire, which is a key element in providing fire safety in buildings with engineering performance-based fire codes. A mathematical model is presented in this paper to predict the flame spreading of materials using the experimental data from cone calorimeter. Numerical prediction of the flame front position and flame sprea...

The problem of flame propagation in imperfectly premixed mixtures—mixtures of reactants with variable composition—is considered in this numerical study. We carry out two-dimensional direct numerical simulations of a flame propagating in a globally lean fuel-oxidizer mixture with imposed velocity and composition fluctuations of various intensities. The configuration adopted is that of a flame fr...

Combustion kinetics ...................................................................................................................................... 1 Physical mixing and its effects on ignition, propagation and extinction ...................................................... 2 Mixing ...........................................................................................................

The objective of this work is to provide physical insight into the mechanisms governing flame–turbulence interactions and explore impact ubiquitous Darrieus–Landau instability on propagation. It based hydrodynamic theory premixed flames that considers flame thickness much smaller than all other fluidynamical length scales. In asymptotic limit, thus confined a surface whilst diffusion reaction p...

Abstract We demonstrate the fabrication of surface nanoscale axial photonics bottle microresonators with angstrom precision using a flame. observe strongly unscalable behavior whispering gallery mode cutoff wavelengths different radial quantum numbers along fibre length.

The thermonuclear explosion of a massive white dwarf in a Type Ia supernova explosion is characterized by vastly disparate spatial and temporal scales. The extreme dynamic range inherent to the problem prevents the use of direct numerical simulation and forces modelers to resort to subgrid models to describe physical processes taking place on unresolved scales. We consider the evolution of a mo...

The effects of flame treatment on the surface characteristics of four injection moulded, automotive grade, polypropylene samples, pigmented with carbon black, have been studied. The changes in wettability have been monitored by water contact angle and Dyne inks, whilst XPS has been used to establish the changes in oxygen surface concentration as a function of flame treatment. As expected carbon...

A correct prediction of the ignition process represents a fundamental pre-requisite for a successful CFD simulation of combustion SI engines. Ignition involves many scales, physical and chemical phenomena that need to be described in detail. Within this context, the authors developed a Lagrangian model that can be used to predict the first stages of the combustion process in SI engines, when th...