Flame instabilities play a dominant role in accelerating the burning front to a large fraction of the speed of sound in a Type Ia supernova. We present a threedimensional numerical simulation of a Rayleigh-Taylor unstable carbon flame, following its evolution through the transition to turbulence. A low Mach number hydrodynamics method is used, freeing us from the harsh timestep restrictions imp...

In a recent numerical paper (Nicoli et al. Combust. Sci. Technol. vol. 186, pp. 103-119; 2014) [1], a model of isobaric flame propagation in lean sprays has been proposed. The initial state of the monodisperse mists was schematized by a system of individual alkane droplets initially located at the nodes of a facecentered 2D-lattice, surrounded by a saturated mixture of alkane and air. In the pr...

A 150 News | Forum flame retardants exposure to tdCPP appears Widespread At a time of growing debate over the safety and usefulness of flame retardants added to consumer products, 1 new evidence is emerging about the breadth of human exposure to one of the most widely used of these compounds. Two new studies 2,3 document the presence of the flame retardant tris(1,3-dichloro-2-propyl) phosphate ...

Our objective is to characterize gravity effects on the structure of laminar methane–air partially premixed flames through detailed simulations. We examine the heat loss due to radiation from similar flames that are established at various gravitational accelerations and coflow velocities. Radiation is modeled using the optically thin assumption that provides a limiting value for the radiation h...

In this study, in-situ bulk polymerization was investigated for obtaining flame retardant polystyrene (PS). The halogenated and phosphoric compounds were used as flame retardant additives and Perkadox 30 was used as a synergist. The flammability of the PS was evaluated by thermogravimetric analyzer (TGA), limiting oxygen index (LOI) and UL-94 tests. The results show that polymerization process ...

Recent advances in automation of systematically reduced mechanisms are reported here with the aim to accelerate the development process. A computer algorithm has been developed enabling fast generation and testing of reduced chemistry. This algorithm has been used to develop various reduced mechanisms of methane-air combustion for modelling of turbulent combustion. A 10-step reduced chemistry h...

Serum sodium and potassium analyses by continuous-flow flame photometry is a well-accepted procedure (1, 2). Recently Habig and Williamson (3) have used the widely available Instrumentation Laboratory Model 143 (IL-143) flame photometer for continuousflow analyses. Pennacchia et al. (4) have operated this flame photometer at rates as high as 120 samples per hour. In both systems the results app...

Unsteady simulations of stagnation point flames are conducted in order to study flame turbulence interactions in a relatively simple flow environment. Flame propagation is represented using a flamelet model called the G equation. Two subgrid models are used to close the filtered G equation. The effects of significant heat release on the turbulent flow and the effect of varying turbulence intens...

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The large range of time and length scales involved in type Ia supernovae (SN Ia) requires the use of flame models. As a prelude to exploring various options for flame models, we consider, in this paper, high-resolution three-dimensional simulations of the small-scale dynamics of nuclear flames in the supernova environment in which the details of the flame structure are fully resolved. The range...