Stabilized combustion

Length. Combustor length must be sufficient to provide for flame stabilization, combustion, and mixing with dilution air. The typical value of the length-to-diameter ratio for liners ranges from three to six. Ratios for casing range from two to four. 

T. Echekki, J. -Y. Ghen, and U. Hedge, Numerical investigation of buoyancy effects on triple flame stability. Combust. Sci. Technol. 176(3) 381-407, 2004. 

M. Matalon and B.J. Matkowsky. Elames in fluids Their interaction and stability. Combust. Sci. Technol., 34 295-316, 1983. 

Figures 12.3 and 12.3c show mean velocity (Fig. 12.36) and mean temperature (Fig. 12.3c) fields under bluff-body stabilized combustion of stoichiometric methane-air mixture at inlet velocity 10 m/s, and ABC of Eq. (12.19) at the combustor outlet. Functions Wj, Wij, and W2j in Eq. (12.1) were obtained by solving the problem of laminar flame propagation with the detailed reaction mechanism [31] of Ci-C2-hydrocarbon oxidation (35 species, 280 reactions) including CH4 oxidation chemistry. The PDF of Eq. (12.4) was used in this calculation.

Figure 12.9 To the determination of the limiting inlet velocity for the stabilized combustion of the stoichiometric methane-air mixture in the combustor with open-edge V-gutter flame holders. Solid curves correspond to the calculated residence time b- Dashed curves correspond to the calculated reaction time tc. Flame holders with H = 10 cm (f), 5 cm (2), and 2 cm (3). Conditions are similar to those in Figs. 12.6 and 12.7...

The Presumed Probability Density Function method is developed and implemented to study turbulent flame stabilization and combustion control in subsonic combustors with flame holders. The method considers turbulence-chemistry interaction, multiple thermo-chemical variables, variable pressure, near-wall effects, and provides the efficient research tool for studying flame stabilization and blow-off in practical ramjet burners. Nonreflecting multidimensional boundary conditions at open boundaries are derived, and implemented into the current research. The boundary conditions provide transparency to acoustic waves generated in bluff-body stabilized combustion zones, thus avoiding numerically induced oscillations and instabilities. It is shown that predicted flow patterns in a combustor are essentially affected by the boundary conditions. The derived nonreflecting boundary conditions provide the solutions corresponding to experimental findings. 

Syred, N., Beer, J. M., "Swirl Stabilized Combustion—a Review, Combust. 

Kendrich, D., Herding, G., Scouflaire, P., Rolon, C., Candel, S. (1999). Effects of a recess on cryogenic flame stabilization. Combustion Flame 118,327-339. 

W C Pfefferle and L D Pfefferle, Catalytically stabilized combustion. Prog Energy Comb Sci 12 25 (me)... 

A/A/Af/V-tetrakis-(2-hydroxyeth-yl)ethylenediamine]. (HOCH2CH2)2NCH2CH2N(CH2CH2OH)2. Properties Clear, viscous liquid. Good heat stability. Combustible. 

Properties Colorless liquid characteristic odor. D 0.891 (20/4C), bp 161-164C (0.3 mm Hg), flash p 385F (196C) (COC). Miscible with most common organic solvents insoluble in water, hydrolyzes very slowly exposure to air should be minimum high thermal stability. Combustible. 

Examples Oxidative coupling of methane (OCM), oxidative dehydrogenation of C -C4 alkanes, partial oxidation of methane to synthesis gasa, combined oxidative coupling of methane and toluene to styrene Surface-stabilized combustion, partial oxidation of methane to synthesis gasa, synthesis of cyanic acid from methane, ammonia, and oxygen3... 

Gupta and his coworkers at the University of Maryland obtained for the first time 3D PIV images of a flame and used these images to interpret airflow characteristics associated with the high-shear regime of the flow (Chapter 12). These features — flame plume and spray flame — are considered to manipulate passive flame control of swirl-stabilized combustion systems. 

Pfefferle, W. C., and Pfefferle, L. D. "Catalytically Stabilized Combustion." Progress in Energy Combustion Science 12 (1986) 25-41. 

The chemical composition of the fibres, their geometry and the spinning conditions define the range of properties glass transition temperature, melting point, heat stability, combustibility, specific electrical resistance, resistance to environment (humidity, chemical, biological, radiation), dye-ability, solubility and the mechanical properties which are listed in the following chapter. The main characteristics of fibres are listed below. 

Appel C, Mantzaras J, Schaeren R, et al. An experimental and numerical investigation of homogeneous ignition in catalyticaHy stabilized combustion of hydrogen/air mixtures over platinum. Combust Flame 128 340-368, 2002a. 

Dogwiler U, Benz P, Mantzaras J Two-dimensional modelling for catalytically stabilized combustion of a lean methane-air mixture with elementary homogeneous and heterogeneous chemical reactions. Combust Flame 116 243—258, 1999. 

Pfefferle WC, Pfefferle LD Catalytically stabilized combustion. Prog Energy Combust Sci 12 25-41, 1986. 

Hung S, Barresi A, Pfefferle L. Flow Tube Reactor Studies of Catalytically Stabilized Combustion of Methyl Chloride. Proceedings of the 23 International Symposium on Combustion. Orleans, France Combustion Institute 1991. p. 909-915. 

Norton DG, Vlachos DG (2004) A CFD study of propane/air microflame stability. Combust Flame 138 97-107... 

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