Gasoline flame behavior at elevated temperature and pressure

Abstract

Freely propagating laminar premixed flames of stoichiometric mixtures of gasoline surrogate and iso-octane with air are computed using three chemical kinetics mechanisms of varied complexity and detail. A good agreement of the computed burning velocities with past experimental data is observed. The burning velocities of these mixtures at temperature of 850 ≤ T ≤ 950 decrease with pressure up to about 3 MPa and starts to increase beyond this pressure. This contrasting behavior is related to the role of pressure dependent reaction involving OH and the influence of this radical on the fuel consumption rate. The results suggest that the overall order of the combustion reaction is larger than two at pressures higher than 3 MPa. Hence, one must be cautious in extending the commonly used laminar flame speed correlation with pressure to thermo-chemical conditions of interest for future engines.

Study on Gasoline–Air Mixture Explosion Overpressure Characteristics and Flame Propagation Behaviors in an Annular Cylindrical Confined Space with a Circular Arch

“…The most dangerous δ values in various confined spaces were slightly different because of different experimental ambient conditions, but were all concentrated at about 1.70% [1,33,34]. In order to study gasoline−air mixture explosion overpressure characteristics and flame propagation behaviors more accurately, the experiments adjusted δ in the range of 1.40−2.00%, including from lean−burn conditions (δ = 1.40%, 1.50%) to suitable−burn conditions (δ = 1.60%, 1.70%, 1.80%) and then to rich−burn conditions (δ = 1.90%, 2.00%).…”

“…The overpressure changing trend, which showed the development law of first increasing and then decreasing as time goes on, was basically the same in different conditions, and demonstrated one obvious overpressure peak (p max ). Li [1], Ghiasi [33] and Mitu et al [34] found that the formation of p max is related to the combustion reaction speed and explosion releasing speed in the gasoline-air mixture explosion process. p max changed significantly at different δ.…”

The Use of the Fourier Series to Analyze the Shaping of Thermodynamic Processes in Heat Engines

“…The Vibe function has many calculation variants [3,35,36] taking into account at least a few parameters, but despite everything, its characteristic shape seems to undergo only a specific stretching or narrowing along the axis of the argument, the crank angle (ca). However, because it was necessary to provide specific parameters of this function, for example, to create graphic illustrations in the further part of the analysis, the influence of several most important parameters necessary to determine the Vibe function was taken into account, which included the following values:…”

Numerical Investigation on Combustion Characteristics of Laminar Premixed n-Heptane/Hydrogen/Air Flames at Elevated Pressure

“…Emission regulations for car engines are becoming more stringent to reduce the environmental impact of fossil fuel combustion in engines. This has forced humans to find new energy and new combustion technologies to provide cleaner, more efficient, heat-efficient combustion with extremely low emissions of NOx, soot, and other pollutants. − High-density gasoline fuel surrogate is a good research object. Gasoline is one of the high-density hydrocarbon fuels with very complex components, so it is difficult to study the combustion process.…”