A computational study is performed to investigate the effects of mixture composition oscillations on a strained premixed methane/air flame. The problem is of practical relevance in direct-injection spark-ignition (DISI) engines and gas-turbines, in which premixed flames propagate through temporally and spatially stratified mixture field. The primary focus of the study is to identify the dynamic...

As a fundamental study in the application to direct-injection spark-ignition engines or gas turbines, in which mixture stratification and partial quenching are of serious concerns, unsteady premixed methane/ air flames subjected to time-varying composition fluctuations are investigated computationally. The code OPUS employs an unsteady opposed-flow combustion configuration, including detailed c...

Heat loss can affect experimental flammability limits, and it becomes indispensable to quantify flammability limits when apparatus quenching effect becomes significant. In this research, the lower flammability limits of binary hydrocarbon mixtures are predicted using calculated flame temperature (CFT) modeling, which is based on the principle of energy conservation. Specifically, the hydrocarbo...

Assessment of the flammability of ornamental vegetation (particularly hedges) planted around houses is necessary in light of the increasing urbanization of the wildland-urban interfaces (WUIs) and the high fire occurrence in such areas. The structure and flammability of seven of the species most frequently planted as hedges in Provence (southeastern France) were studied at particle level. Spati...

The motivation for this project is to develop a hydrocarbon-based (ER12) refrigerant that has a lower flammability limit in excess of 5% refrigerant in air. Optimisation of the hydrocarbon content in the mixture, favourable refrigeration properties, minimal toxicity and benign environmental impact form additional constraints. A variety of compounds were considered as potential flammability redu...

Introduction Regardless of how horrible and devastating wildland fires are portrayed by the media, they are a natural disturbance that many native ecosystems depend on for regeneration. As the population of the United States increases, more individuals are building their homes in wildlands rather than urban landscapes. Homes built in undeveloped wildland vegetation create areas often referred t...

This paper presents data on the limiting (minimum) oxygen concentration (LOC), in the presence of added N2, of methane (CH4), propane (C3H8), ethylene (C2H4), carbon monoxide (CO), and hydrogen (H2), and some of their binary mixtures. It also addresses the issue of the flammable concentration (flammability) limits of these pure gases in air. The study is based on spark ignited explosions in lar...

The idea that flammability has evolved in man) tire-prone communities has been criticised for being group-selectionist. However flammability may enhance inclusive fitness if the resulting tires kill neighbouring less flammable indi\iduals and also open recruitment possibilities. We modelled the evolution ot flammabilits usmg cellular automata to simulate neighbourhood effects of burning. For pl...

The objectives of this paper are to assess in laboratory conditions the flammability of undisturbed litter sampled beneath plants of seven species that are among those most frequently planted in hedges in Provence (southeastern France). Results were the variability in flammability recorded during burning experiments performed on undisturbed litter samples were partly explained by the proportion...

A new apparatus has been constructed to investigate the quenching of laminar hydrocarbon-air flames, at elevated initial pressures. The pressure-tight quenching channel is of trapezoidal form, with very smooth decrease of the channel width along its one meter length that is almost equivalent to a parallel-plate flame arrester. Propane-air mixture has been tested on the entire flammability domai...