The objective of this work was to investigate the influence of preferential diffusion on flame structure and propagation of lean-premixed hydrogen-carbon monoxide syngas-air flame at elevated pressure using direct numerical simulation (DNS) and detailed chemistry. The physical problem investigated is lean-premixed H2/CO outwardly propagating turbulent spherical flame at constant pressure of 4ba...

Experiments were conducted on laminar spray diffusion flames of ethanol/argon burning in oxygen at pressures of 1 and 3 atm. The flames were physically characterized by measuring droplet velocities and sizes by phase-Doppler anemometry, and gas temperature by thin-filament pyrometry and thermocouples. The flames exhibited a cold core, where little vaporization occurred, surrounded by a primary ...

An idealized geometry corresponding to a premixed flame in stagnation-point flow is used to investigate the effects of catalysis on extending the extinction limits of nonadiabatic stretched flames. Specifically, a surface catalytic reaction is assumed to occur on the stagnation plane, thereby augmenting combustion in the bulk gas with an exothermic surface reaction characterized by a reduced ac...

Synthetic polymeric materials are rapidly replacing more traditional inorganic materials, such as metals, and natural polymeric materials, such as wood. As these synthetic materials are flammable, they require modifications to decrease their flammability through the addition of flame-retardant compounds. Environmental regulation has restricted the use of some halogenated flame-retardant additiv...

This paper examines the use of plasma discharges in flame stabilization. Three different types of plasma discharges are applied to a lifted jet diffusion flame in a coflow configuration, and evaluated for their abilities to enhance flame stabilization. A single electrode corona discharge (SECD) between a platinum electrode and the flame base is found to maintain the flame at a 20% higher coflow...

The effects of channel width, wall temperature, and flow rate on the dynamics of non-premix flames in a mesoscale combustor were studied in methane and propane–air mixing layers. A flame street structure which consists of multiple triple flamelets in the mixing layer of the reactants was observed experimentally for the first time. Depending on the flow rate, it was found that there are two diff...

Flame instabilities play a dominant role in accelerating the burning front to a large fraction of the speed of sound in a Type Ia supernova. We present a threedimensional numerical simulation of a Rayleigh-Taylor unstable carbon flame, following its evolution through the transition to turbulence. A low Mach number hydrodynamics method is used, freeing us from the harsh timestep restrictions imp...