The significance of intermediate hydrocarbons during wall quench of propane flames

Kiehne, Thomas M.; Matthews, Ronald D.; Wilson, Dennis

doi:10.1016/s0082-0784(88)80276-5

Cited by 21 publications

(7 citation statements)

References 17 publications

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“…Then HOQ configuration has been studied for various wall temperatures and mixture equivalence ratios. It appeared that the quenching Peclet number and wall heat flux showed very good agreements with precedent studies [24,31]. The use of a multi-step mechanism allowed to measure the impact of the heat transfers at the wall on the formation of HC.…”

Section: Discussionmentioning

confidence: 55%

“…These fuels have limited pathways of forming HC during the combustion. Concerning fuels with more important molecular weight, which have more HC pathways formations, it has been shown [24,31] that the quantity of total HC exceed the quantity of pure fuel. Consequently, it is preferable to use a complex chemistry that takes into account several pathways of forming HC and interactions between transport and oxidation in the gas.…”

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confidence: 99%

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Flame/Wall Interactions: Laminar Study of Unburnt HC Formation

Chauvy

Delhom

Réveillon

et al. 2010

Flow Turbulence Combust

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This work presents a numerical study dedicated to the formation of unburnt hydrocarbon. Two configurations: head-on quenching (HOQ) on a planar wall and in crevices, are considered. It is well known that they contribute for an important part to the sources of hydrocarbon (HC) emission in a combustion chamber. The aim of this work is to use laminar flame simulations (LFS) to understand how the unburnt HC are produced near walls in gasoline engine. A skeletal mechanism (29 species and 48 reactions) mimicking iso-octane combustion is used. In the HOQ configuration, the flame front propagates toward the cold wall where quenching occurs. The numerical procedure and the chemical scheme used in this study are first validated by comparisons with literature results for the 1D case. Several aspects of flame wall quenching such as oxidation of unburnt HC, wall heat flux, quench distances as well as HC families are investigated by varying parameters like wall temperature and equivalence ratio. In a second part, crevices are considered to study the impact of wall imperfections in combustion chambers. Configurations with different geometrical and thermodynamic properties are tested. It leads to a wide range of flame properties and HC production modes. When incomplete combustion occurs, total HC (fuel + HC) concentration can reach very high levels at the wall. When the crevice is not wide enough, the flame cannot propagate and the quantity of HC is smaller than in the case where the flame can propagate (but the fuel is not oxidizing). If the crevice is wide enough for the flame to propagate, HOQ occurs at 1 the bottom of the crevice and HC accumulate in the corners. The computational results obtained in this work demonstrate the ability of LFS to reproduce incomplete combustion mechanisms that are responsible for a major part of HC production in gasoline engines.

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Section: Discussionmentioning

confidence: 55%

mentioning

confidence: 99%

Flame/Wall Interactions: Laminar Study of Unburnt HC Formation

Chauvy

Delhom

Réveillon

et al. 2010

Flow Turbulence Combust

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“…Heat transfer has a significant impact on the efficiency of an engine, lowering the usable work when heat transfer rates to the chamber walls are high. Finally, the effect of wall temperature on unburned hydrocarbon emissions from the quench layer has been the topic of several investigations [1][2][3].…”

Section: Introductionmentioning

confidence: 99%

“…Such parameters include wall temperature (T w ), equivalence ratio ( ), chamber pressure, and surface reactivity [1][2][3][4][5][6][7][8][9][10][11][12][13]. Popp [4] found using direct numerical simulation (DNS) that the peak heat release rate of propane/air flames occurs directly at the surface for isothermal wall temperatures above 400 K. Sotton et al [5] determined that the wall heat flux increases non-linearly with increasing chamber pressure for methane flames.…”

Section: Introductionmentioning

confidence: 99%

Interactions of hydrogen flames with walls: Influence of wall temperature, pressure, equivalence ratio, and diluents

Owston

Magi

Abraham

2007

International Journal of Hydrogen Energy

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“…The interaction between combustible gases and surfaces is important in determining emissions from a system. Excess emissions of unburned hydrocarbons in combustion engines have long been attributed to the presence of cool walls (Daniel, 1956;Westbrook et al, 1981;Kiehne et al, 1986;Hocks et al, 1981;Sloane and Schoene, 1983). In a related problem, the conversion of NO to NO, when a combusted gas comes in contact with the wall of water-cooled measurement probes has evoked some interest and speculation about the accuracy of NO, measurements (Hori, 1986).…”

Section: Introductionmentioning

confidence: 99%