This work focuses upon the effects of DC electric fields on the stability of downward propagating atmospheric pressure premixed propane–air flames under experimental conditions that provide close coupling of the electric field to the flame. With the appropriate electrode geometry, modest applied voltages are shown to drive a stable conical flame first into a wrinkled-laminar flamelet geometry, ...

Turbulent-flame speeds in methane–air mixtures were measured in a Taylor–Couette apparatus with counter-rotating cylinders, used to generate turbulence that is nearly homogeneous and isotropic over many integral length and time scales. While laminar-flame propagation is found to be influenced by the Darrieus– Landau instability and heat loss to the walls of the apparatus, turbulent-flame propag...

In this study, the dependence of minimum ignition energies (MIE) on geometry, source radius and mixture composition is investigated numerically for methane/air iso-octane/air mixtures. Methane iso-octane are both important hydrocarbon fuels, but differ strongly with respect to their Lewis numbers. Lean air mixtures have particularly large The results show that within flammability limits, MIE st...

In an opposed-jet diffusion flame experiment, under certain conditions, after the extinction of the diffusion flame, an edge flame can be obtained. This ring-shaped edge flame was first reported in 1959 by Potter and Butler but received little attention. It was reported again recently in a numerical and an experimental work and is responsible for an interesting transition between two distinct b...

A thermodynamic model has been developed to calculate burning speed and entropy production of transient expending spherical laminar flame in an enclosed vessel. The model also predicts the particle trajectories of both unburned and burned gases in the vessel. The input to this model is the dynamic pressure rise due to combustion process. The unburned gases are divided into three regions: The co...

An experimental study on pressure evolution during closed vessel explosions of several gaseous fuel-air mixtures was performed, at various initial pressures within 0.3-1.2 bar and ambient initial temperature. Explosion pressures and explosion times are reported for methane-, n-pentane-, n-hexane-, propene-, butene-, butadiene-, cyclohexane- and benzene-air mixtures. The explosion pressures meas...

A computational heat and mass transfer model of ceramic precursor solution containing droplets injected into a combustion flame is presented. Upon heat-up and vaporization, the precursor in droplets precipitate and ultimately form the ceramic material. Temperature and solute concentration distributions were computed to estimate the precipitation zones within droplets based on a simple homogeneo...

Ceria nanoparticles are one of the key abrasive materials for chemical-mechanical planarization of advanced integrated circuits. However, ceria nanoparticles synthesized by existing techniques are irregularly faceted, and they scratch the silicon wafers and increase defect concentrations. We developed an approach for large-scale synthesis of single-crystal ceria nanospheres that can reduce the ...

Abstract The ignition sensitivity and flame propagation of titanium dust cloud were investigated to evaluate the risk combustion explosion powder. minimum temperature(MIT) was determined by Godbert-Greenwald furnace energy(MIE) Hartmann apparatus. behavior in apparatus recorded high-speed camera infrared thermal imager. results show that spherical powder with a median diameter 12.5μm had temper...

An improved spark ignition model has been developed and implemented into the KIVA-3V code. In this model, the spark ignition kernel growth is tracked by Lagrangian particle markers. The effects of turbulent flow and spark discharge energy on the kernel growth are considered. After the ignition kernel size exceeds a critical size related to the integral turbulent length scale of the flow, the tu...