Autoignition and combustion of n-hexane spray in subcritical and supercritical environments

Abstract

In this study, processes of a liquid fuel spray ignition and heat release during its combustion were under investigation. The purpose of this study was to elucidate whether the ignition properties and heat release process of a liquid fuel injected into the environments of parameters exceeding its critical values differ from those obtained for subcritical regimes. Therefore, the fuel was injected into the environments of parameters below, around and above its critical values. The ignition and combustion processes were observed by monitoring the pressure in the combustion chamber and by using a high-speed camera through transparent piston. The ignition process was characterized by ignition delay, while the combustion process by heat release and rate of heat release. The ignition delay was determined by pressure rise according to tangential method. Ignition delay determined that way included both physical delay and chemical delay. Obtained results revealed stochastic nature of the spray ignition of n-hexane. No major difference in ignition delay in terms of exceeding critical parameters was noticed. The only parameter directly influencing the ignition delay was the injectant initial temperature.

The influence of internal catalyst on exhaust emission in dynamic conditions

“…Based on this analysis, it can be concluded that the improvement of ecological and economic parameters of combustion engines depends primarily on the correct execution of the combustion process -depending largely on the activation energy and on the presence of a catalyst increasing the rate of chemical reactions [7,8]. Therefore, it is proposed that this internal catalyst should be used as an outer surface for selected combustion chamber elements.…”

Various aspects of research of the SI engine with an additional expansion process

“…However, despite the introduction of advanced technical solutions for the engines themselves as well as the exhaust aftertreatment systems, it is not possible to completely eliminate the problem of emissions from the powertrains with combustion engines. Consequently, interest in electric vehicles has increased over the past 20 years [3]. The pure electric drive for vehicles has the advantage that the vehicle does not emit toxic components or CO 2 in the area where it is used.…”

The experimental determination of the relationship between the energising time of the common rail injector and the set fuel quantity and rail pressure

“…in general, the overall volume-time characteristics of the fuel injection process significantly affect the heat release and, consequently, the engine performance, as well as the contents of harmful substances in the exhaust gas, including solid particles (mainly soot), and the noise generated by the engine in operation [4][5][6][7].…”