In this paper, we study the performance of a testing apparatus that could be used for evaluating the effectiveness of gaseous suppressants and solid fuel retardants under opposed flame spread conditions. A narrow channel, 3 mm in height, 110 mm in width and 375 mm in length, constitutes the most important component of this apparatus. To establish the flow and flame spread parameters in this app...

We explore the detailed structure of heat release and the energy budget for a freely-propagating lean, premixed hydrogen flame. At lean conditions, the flame is thermodiffusively unstable and spontaneously develops the cellular burning structures, characteristic of this type of flame. The instabilities in the system saturate quickly, resulting in robust, slowly evolving cellular burning feature...

It is known that unconfined dust explosions typically start off with a relatively weak primary flame followed by a severe secondary explosion. We show that clustering of dust particles in a temperature stratified turbulent flow ahead of the primary flame may give rise to a significant increase in the radiation penetration length. These particle clusters, even far ahead of the flame, are suffici...

Multiple flame-flame interactions in premixed combustion are investigated using Direct Numerical Simulations of twin turbulent V-flames for a range of turbulence intensities and length scales. Interactions are identified using a novel Automatic Feature Extraction (AFE) technique, based on data registration using the Dual-Tree Complex Wavelet Transform. Information on the time, position and type...

The influence of strong rotation on the flame length in firewhirls (normalized by the fuel supply rate) is investigated analytically. A new prediction for the length of the flame in firewhirls with strong rotation is obtained by introducing the compensating regime of vortical flows. The prediction is in a good agreement with experimental results.

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...

The optimum length of a monolith tube is one for which near-hundred percent conversion is attained, and at the same time, the catalyst over the ntire length of the tube is utilized. In practice, the length is adjusted by stacking monolith plugs end-to-end. In this study, the repercussions of uch a practice are investigated numerically with the goal to determine if a tube of length 2L demonstrat...

temporal and spatial variations of fire behavior can be predicted using one of the semi-physical or empirical models developed over recent years. this article investigates the effect of different fuel moisture conditions on fire spread and behavior in national golestan park in july 2011 using farsite, flammap simulation systems, and previous ignition history. landscape data contains the topogra...

A steady source of buoyancy creates a plume. Experi­ mental and theoretical studies of plumes have been mainly concerned with the far-field (self-similar) velocity and den­ sity profiles. •-3 Yet in many practical situations, knowledge regarding the rate of molecular scale mixing of the buoyant fluid with its environment is needed. This is especially true in the context of atmospheric studies, ...