Large-eddy simulation of premixed combustion is a computational challenge, because complex diffusion and reaction processes often occur in very thin layers. The interaction of these processes with turbulence determines the main properties of the flame brush, such as its burning velocity or its thickness. In turbulent flows, the large vortices wrinkle the flame brush and increase its surface, wh...

Rayleigh scattering temperature measurements were obtained in a turbulent reactive swirling coaxial jet discharged from a swirl-stabilized burner along the jet-flame centerline. They are reported up to 10 fuel nozzle diameters downstream of the burner exit at a Reynolds number of 29000. The effect of swirl numbers (S=0.3, 0.58, 1.07) on the temperature fields, the power spectral density of temp...

The study of premixed laminar flames is a central question in combustion theory. Here the differential equations describing steady flame propagation are investigated mathematically. The emphasis is on analytic results, hence a simple model, a onestep exothermic reaction with linear or radiative heat loss is studied. The equations governing our model can be considered as travelling wave equation...

Microgravity experiments were conducted in the 2.2-s drop-tower facility at the NASA Glenn Research Center to study the transient response of the burner-generated spherical diffusion flame caused by its initial displacement from the steady-state position. The experiment involved issuing H2/CH4/inert mixtures of constant fuel mass flow rates from a bronze, porous, 1.27-cm-diameter, spherical bur...

The differences need to be understood between the leading order jump conditions, often assumed at a flame sheet in combustion theory, and the actual effect of a one step chemical reaction governed by Arrhenius kinetics. These differences are higher order in terms of a large activation temperature analysis and can be estimated using an asymptotic approach. This paper derives one order of asympto...

nanoclay/triphenyl phosphate hybrid system was employed to examine the fire retardancy and mechanical properties of pc/abs blends. each of the polymers and their blends are widely used in the automotive, electrical andelectronic industries. because most thermoplastics are easily combustible they need to be flame retarded to reduce the burning rate especially in the initial phase of a fire incid...

Title of Dissertation: High Temperature Radiation Absorption of Fuel Molecules And An Evaluation of Its Influence on Pool Fire Modeling Kaoru Wakatsuki Doctor of Philosophy, 2005 Dissertation Directed By: Associate Professor, Jungho Kim Associate Professor, Greg Jackson Department of Mechanical Engineering Infrared absorption coefficients of various gas and liquid fuels (propane, nheptane, meth...

Rayleigh scattering temperature measurements were obtained in a turbulent reactive swirling coaxial jet discharged from a swirl-stabilized burner along the jet-flame centerline. They are reported up to 10 fuel nozzle diameters downstream of the burner exit at a Reynolds number of 29000. The effect of swirl numbers (S=0.3, 0.58, 1.07) on the temperature fields, the power spectral density of temp...

We report in situ, real-time detection of soot particles coated with NaCl using excimer laser fragmentation fluorescence spectroscopy (ELFFS). Carbon atom fluorescence at 248 nm and the Na D-line at 589 nm are used as signatures of soot and NaCl, respectively. Soot particles are encapsulated with a NaCl layer in a well-controlled inverted flame burner. NaCl particles are injected into the metha...

The interaction of turbulent nonpremixed flames with fine water spray is studied using direct numerical simulations (DNS) with detailed chemistry. The study is of practical importance in fire safety devices that operate in the mist regime, as well as an inexpensive temperature control mechanism for gas turbines. The implemented computational methods for the Lagrangian particle-in-cell spray dro...