Regime combustion

V. Nayagam and F. A. Williams, Curvature effects on edge-flame propagation in the premixed-flame regime, Combust. Sci. Tech. 176 2125-2142,2004. 

Agrafiotis, C. C Puszynski, J. A., and Hlavacek, V., Experimental study on the synthesis of titanium and tantalum nitrides in the self-propagating regime. Combust. Sci. Tech., 76, 187 (1991). 

Maksimov, Y. M., Ziatdinov, M. K. Raskolenko, A. G., and Lepakova, O. K., Interaction between vanadium and nitrogen in the combustion regime. Combust. Explos. Shock Waves, 15, 420 (1979). 

Emissions from methanol vehicles are expected to produce lower HC and CO emissions than equivalent gasoline engines. However, methanol combustion produces significant amounts of formaldehyde (qv), a partial oxidation product of methanol. Eormaldehyde is classified as an air toxic and its emissions should be minimized. Eormaldehyde is also very reactive in the atmosphere and contributes to the formation of ozone. Emissions of NO may also pose a problem, especiaHy if the engine mns lean, a regime in which the standard three-way catalyst is not effective for NO reduction. 

The life and necessary maintenance of a gas turbine are heavily dependent upon both the operating regime and the fuel quality. Continuous firing on natural gas provides the optimum availability, which will be progressively eroded if the plant is subject to frequent inter-mptions (i.e. stops and starts) from both cold and hot conditions. With a maximum interval between inspections of some 8000 hours, it may be anticipated that the combustion section will require most attention. Every 16,000 hours (or less) the turbine section will need inspection. While a major inspection of the entire unit will be necessary every 31,500 hours. Under optimal conditions, the... 

II is via penetration of hot combustion products into the existing pores of the expl. Propagation in Region III is via convective flow between the charge surface and its confinement. This regime is claimed to be affected by confinement expansion (due to pressure), and by fragmentation of the peripheral portions of the expl column. The phenomena in Regions IV and V have already been described in Section VIII under Initiation by Impact Friction... 

M. L. Bernard et al, CRAcadSci, Ser C, 272 (26), 2112-15 (1972) CA.75, 101675 (1971) A generalization of the previously described (Bernard et al, 1971) ablation theory (for AP) combustion to include AP-based solid propints provides satisfactory fits to the exptl data of M. Summerfield et al (1960), with reproduction of the two distinct pressure regimes observed in the combustion of AP-based powders between 0 and 100 bars. The solid binding agent is assumed to be easily pyrolyzable, with each mol producing several combustible gaseous mols, as in the case of pyrolytically degrading polymers... 

The spouting regime of fluidization is used for the fluid-solid noncatalytic reactions, especially drying and combustion. 

Laminar flame speed is one of the fundamental properties characterizing the global combustion rate of a fuel/ oxidizer mixture. Therefore, it frequently serves as the reference quantity in the study of the phenomena involving premixed flames, such as flammability limits, flame stabilization, blowoff, blowout, extinction, and turbulent combustion. Furthermore, it contains the information on the reaction mechanism in the high-temperature regime, in the presence of diffusive transport. Hence, at the global level, laminar flame-speed data have been widely used to validate a proposed chemical reaction mechanism. 

Behavior of edge propagation speed with concentration gradient (A transition, B tribrachial, C bibrachial, D monobrachial and near extinction regimes). (From Chung, S.H., Proc. Combust. Inst., 31, 877,2007.)... 

In the so-called "wrinkled flame regime," the "turbulent flame speed" was expected to be controlled by a characteristic value of the turbulent fluctuations of velocity u rather than by chemistry and molecular diffusivities. Shchelkin [2] was the first to propose the law St/Sl= (1 + A u /Si) ), where A is a universal constant and Sl the laminar flame velocity of propagation. For the other limiting regime, called "distributed combustion," Summerfield [4] inferred that if the turbulent diffusivity simply replaces the molecular one, then the turbulent flame speed is proportional to the laminar flame speed but multiplied by the square root of the turbulence Reynolds number Re. ... 

Turbulent mass burning rate versus the turbulent root-mean-square velocity by Karpov and Severin [18]. Here, nis the air excess coefficient that is the inverse of the equivalence ratio. (Reprinted from Abdel-Gayed, R., Bradley, D., and Lung, F.K.-K., Combustion regimes and the straining of turbulent premixed flames. Combust. Flame, 76, 213, 1989. With permission. Figure 2, p. 215, copyright Elsevier editions.)... 

Such experiments have also allowed a better understanding concerning the turbulent combustion regimes, which extends the earlier foundation works mentioned in the introduction, and revisited by Barrere and Borghi [30,31] and others [32,33]. New intermediate combustion regimes have been delineated, thanks to the instantaneous flame front imaged through simultaneous 2D measurements. 

Premixed turbulent combustion regime diagram proposed by Chen and Bilger. Two intermediate regimes are delineated between distributed flame front and wrinkled laminar flamelets. (Reprinted from Chen, Y.C. and Bilger, R., Combust. Flame, 131, 400, 2002. With permission. Figure 9, p. 411, copyright Elsevier editions.)... 

R. Abdel-Gayed, D. Bradley, and F.K.-K. Lung 1989, Combustion regimes and the straining of turbulent premixed flames. Combust. Flame 76 213-218. 

F. Dinkelacker 2003, Experimental validation of flame regimes for highly turbulent premixed flames. Proceedings of the First European Combustion Meeting ECM2003. See also the 27th Symp.(Int.) on Combustion, pp. 857-865, 1998. 

In the 1950s, the more descriptive schlieren records of the interactions between pressure waves and deflagration fronts were obtained [16-18], and Oppenheim [9] introduced the hypothesis of the "explosion in the explosion" (of the detonating mixture) occurring in the regime of accelerating flame to explain the sudden change in the velocity of the combustion wave observed in the experiments. 

Zel dovich Ya.B., Regime classification of an exothermic reaction with non-uniform initial conditions. Combust. Flame, 39,211,1990. 

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