The effects of fuel stream dilution on the liftoff, stabilization, and blowout characteristics of laminar nonpremixed flames NPFs and partially premixed flames PPFs are investigated. Lifted methane-air flames were established in axisymmetric coflowing jets. Because of their flame suppression characteristics, two predominantly inert agents, CO2 and N2, were used as diluents. A time-accurate, imp...

The near-field of an azimuthally excited round jet was investigated in a combined computational/ experimental study. The reaction zones in the jet were visualized using OH Planar-LaserInduced-Fluorescence ~PLIF! diagnostics. Both axisymmetric and azimuthal modes of the jet were excited to stabilize its spatial structure. Three-dimensional flame visualization of the laboratory jet reconstructed ...

For the case of flame thickness being of the order of the pore linear dimension, the flame structure and speed in adiabatic, premixed methane-air combustion in porous media are examined. The local, volume-averaged conservation equations that assume a local thermal equilibrium between the solid and the gas phases (i.e. the single-medium treatment) or allow for a thermal nonequilibrium (i.e. the ...

The effect of electric fields on combustion is well established [1]. However, few studies have been conducted about the effect of magnetic fields on combustion, though the fact that magnetic fields can influence combustion was first realized over one hundred and fifty years ago. As early as 1846, Faraday applied a magnetic field to a flame on a wax taper and observed its tendency to form an equ...

The effect of electric fields on combustion is well established [1]. However, few studies have been conducted about the effect of magnetic fields on combustion, though the fact that magnetic fields can influence combustion was first realized over one hundred and fifty years ago. As early as 1846, Faraday applied a magnetic field to a flame on a wax taper and observed its tendency to form an equ...

A numerical study of the supercritical combustion of a liquid oxygen (LOX) droplet in a stagnant environment of hot hydrogen is carried out with a detailed chemistry model. Special attention is devoted to ignition process and diffusion flame structure. Ignition consists typically of the propagation of a premixed flame which is initiated in the H,-rich hot side. Propagation takes place in a nonh...

A spectral formalism has been developed for the “non-intrusive” analysis of parametric uncertainty in reacting-flow systems. In comparison to conventional Monte Carlo analysis, this method quantifies the extent, dependence, and propagation of uncertainty through the model system and allows the correlation of uncertainties in specific parameters to the resulting uncertainty in detailed flame str...