Effects of chemically-passive fire suppressants on laminar premixed hydrogen flames were investigated by combined use of microgravity experiments and computations. The experiments used a short-drop free-fall laboratory facility that provides at least 450 ms of 2 10 g. Near -limit laminar burning velocities were measured for outwardly propagating spherical stoichiometric hydrogen-air flames with...

this study focuses on achieving high stiffness/strength and good fr characteristic of nylon 66/mca/nc nanocomposites, prepared via melt compounding by twin screw extruder. a synergistic effect of flame retardant systems based on melamine cyanurate and zinc borate on the flammability and mechanical behaviours of crysnanoclay reinforced nylon 66 nanocomposites have been reported. mechanical test ...

A computational study is performed to investigate the effects of hydrogen addition on the fundamental characteristics of stretched methane/air premixed flame in an opposed flow configuration. The problem is of interest as a potential application to gas turbines and spark-ignition engines, where it has been anticipated that addition of a small amount of hydrogen will extend the lean flammability...

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...

A new analytical study performed to investigate the effect of the temperature difference between gas and particle in propagation of the spherical flames. The combustible system is containing uniformly distributed volatile fuel particles in an oxidizing gas (Air) mixture. The model includes evaporation of volatile matter of dust particles to known gaseous fuel (methane) and the single-stage reac...

The flame stability limit, which was involving the critical flow condition, lift off and blow out, could be affected by the burner geometry in the combustion system installation. Consequently a flame holder should be put in, to hold the flame as big as possible on a stable condition. The flame holder itself, is a device to hold the flame, whereas the flame holder could disturb the air and fuel ...

Long-term fire retardants are used to prevent the spread of wildland fire, but have inadvertently entered aquatic habitats and resulted in fish kills. We examined the toxicity of two fire retardant products; PHOS-CHEK 259F and LC-95A, on Chinook salmon with two different life histories, ocean-type and stream-type, at different stages of their development. Ocean-type Chinook outmigrate to the oc...

The four processes involved in the flammability of materials are described and related to the various flame retardance mechanisms that may operate. Following this the four practical approaches used in improving flame retardance of materials are described. Each approach is illustrated with a number of typical examples of flame retardants or synthetic procedures used. This overview of flammabilit...

The objective of this experiment is to better understand the combustion behavior of pulsed, turbulent diffusion flames by conducting experiments in microgravity. The fuel jet is fully-modulated (i.e., completely shut off between pulses) by an externally controlled valve system leading to enhanced fuel/air mixing compared to acoustically excited or partiallymodulated jets[1]. Experiments are con...