Characteristics of methanol diffusion flames burning under three different configurations with respect to the directions of forced and natural convective flow fields are presented for zero and normal gravity conditions. Combustion of a spherical methanol particle and of a methanol film within a mixed convective environment, have been numerically simulated. The effects of gravity on aiding, oppo...

Synthesis and characterization of long wavelength visible-light absorption Cu-doped TiO2 nanomaterials with well-controlled properties such as size, composition, morphology, and crystal phase have been demonstrated in a single-step flame aerosol reactor. This has been feasible by a detailed understanding of the formation and growth of nanoparticles in the high-temperature flame region. The impo...

Combustion under high-pressure conditions holds the potential for improved thermodynamic efficiency, enhanced power generation, and reduced emission of some pollutants. It underlies the technology of internal combustion engines such as the automotive engine, the gas turbine, and the rocket engine, for which the operating pressure can reach as high as 100s atm. At such high-pressure conditions, ...

Recent experimental investigations of combustion in diesel engines showed that the initial premix burn creates pockets of soot and fuel that must burn out in a diffusion-flame mode in order to complete the combustion [5, 6]. Understanding the final stages of this process is critical to predicting the emissions of soot and NOx. This effort uses numerical simulations to investigate burnout of dif...

A direct Path Flux Analysis (PFA) method for kinetic mechanism reduction is proposed and validated by using high temperature ignition, perfect stirred reactors, and steady and unsteady flame propagations of n-heptane and n-decane/air mixtures. The formation and consumption fluxes of each species at multiple reaction path generations are analyzed and used to identify the important reaction pathw...

Three-dimensional direct numerical simulations are performed of turbulent combustion of initially spherical flame kernels. The chemistry is described by a progress variable which is attached to a flamelet library. The influence of flame stretch and curvature on the local mass burning rate is studied and compared to an analytical model. It is found that there is a good agreement between the simu...

Please cite this article in press as: L. Qiao, Com A detailed numerical study was conducted to understand the transient flame propagation process and the flame-speed oscillation phenomenon in a carbon dust cloud. The modeling included the solution of a set of time-dependent conservation equations developed for the gas phase and the particle phase in a spherical coordinate. The gas-phase reactio...

Europium-doped yttrium silicate (Y2SiO5:Eu ) nanophosphors were successfully synthesized by flame spray pyrolysis method. The effect of silicon concentration on the crystal structure and morphology of the Y2SiO5:Eu 3+ phosphors were investigated. Asprepared phosphor consists of spherical nanoparticles with filled morphology, high crystallinity, narrow size distribution, and intense photolumines...

Using zinc naphthenate dissolved in xylene as a precursor undoped ZnO nanopowders were synthesized by the flame spray pyrolysis technique. The average diameter and length of ZnO spherical and hexagonal particles were in the range of 5 to 20 nm, while ZnO nanorods were found to be 5-20 nm wide and 20-40 nm long, under 5/5 (precursor/oxygen) flame conditions. The gas sensitivity of the undoped Zn...

Based on the self-built experimental setup, propagation law of explosion flame hydrogen/methane premixed gas with different hydrogen volume fractions in equivalent ratios was investigated under action a corrugated fire-retardant core. The study shows that isolation and suppression effect core at equivalence is either promoted or suppressed, quenched without mixing when ?=0.8and1.0, also ?=1.2in...