A dominant factor in determining the burning rate of a premixed turbulent flame is the degree to which the flame front is wrinkled by turbulence. Higher turbulent intensities lead to greater wrinkling of the flame front and an increase in the turbulent burning rate. This picture of turbulent flame dynamics must be modified, however, to accommodate the affects of variations in the local propagat...

Nanocomposites of encapsulated silica nanoparticles were prepared by in situ emulsion polymerization of acrylate monomers. The synthesized material showed good uniformity and dispersion of the inorganic components in the base polymer, which enhances the properties of the nanocomposite material. A nonionic surfactant with lower critical solution temperature (LCST) was used to encapsulate the sil...

This paper describes the non-linear dynamics of premixed flames responding to harmonic velocity disturbances. It extends a prior computational study which determined the key parameters influencing the nonlinear flame characteristics. It was shown that the linear and nonlinear characteristics of the flame dynamics were controlled by the superposition of two sources of flame disturbances: those o...

The present project was conducted with the circumferential-fuel-jets inverse diffusion flame (CIDF) burner burning liquefied petroleum gas (LPG) enriched with 50% of hydrogen fuel (H2). The range of stable operation of the CIDF burner in terms of Reynolds number (from laminar to turbulent flow regions), equivalence ratio and fuel jet velocity of LPG of the 50% H2-LPG mixed fuel was identified. ...

The effects of imposed flow velocity on flame spread along open edges of a thermally thin cellulosic sample in microgravity were studied experimentally and theoretically. In this study, the sample was ignited locally at the middle of the 4 cm wide sample, and subsequent flame spread reached both open edges of the sample along the direction of the flow. The following flame behaviors were observe...

This study was aimed to determine combustion characteristics and decay resistance of Spruce [Picea orientalis (L.)], Fir (Abies nordmanniana), Alder [Alnus glutinosa (L.)], and Iroko (Milicia excelsa) woods impregnated with ammonium tetrafluoro borate (1 to 3%) and the mixture of cement and borax (6% to 9%). The combustion test method was performed in three stages: flame stage, without flame st...

In this paper, the effect of air turbulence intensity on the flame structure in various radii and lengths of a flame holder numerically studied. Finite volume method is used to solve the governing equations. The obtained numerical results using realizable k-ε and β-PDF models show a good agreement with the experimental data. The results show that flame holder with greater lengths yield shorter ...

A new model for turbulent flame velocity of premixed flame in spark ignition engine for Iso-octane air mixture has been developed and validated for a wide range of engine operating parameters. The model developed is a zero dimensional thermodynamic model. The effects of engine speed (600-1160 rpm), equivalence ratio (0.7-1.1), unburnt mixture temperature (532650 Rankine), compression ratio (5-8...

The interaction of a premixed methane/air flame with a counter-rotating vortex pair is analyzed using a parallel low-Mach-number computational model that is based on a detailed C1C2 chemical mechanism. Attention is focused on the transient response of the heat release rate and the flame structure at the centerline of the vortex pair. Results are obtained for vortex pairs of different strengths ...

This paper presents an experimental study on the dynamics of a ducted, conical, laminar premixed flame subjected to low amplitude acoustic excitation from upstream. The heat release response of the flame to velocity disturbances is investigated through measurement of the so called ‘flame transfer function’ for a wide range of forcing frequencies. The results are compared with those predicted by...