This computational study is motivated by recent experiments on large-scale cookoff in a confined annular geometry, where the explosive charge is heated carefully so as to produce, nominally, a uniform radial thermal gradient. In the absence of circumferential asymmetry a circular wave of explosion would traverse the charge from the hot outer boundary to the cold inner boundary. In practice, how...

0016-2361/$ see front matter 2012 Elsevier Ltd. A doi:10.1016/j.fuel.2012.01.042 ⇑ Tel.: +90 262 3032285; fax: +90 262 3032203. E-mail address: [email protected] Homogeneous charge compression ignition (HCCI) combustion mode has some benefits compared to the most popular conventional combustion forms used in the internal combustion (IC) engines: spark ignition (SI) and compression igni...

Ignition is the initial stage of burning the materials. Consequent flame spread over the materials, heat release rate, fire spread across the rooms, and other issues for building fires all depend on that. Ignition of cellulose materials is commonly classified as smoldering or glowing ignition (self-heating ignition) and flaming ignition including piloted and spontaneous ignition. Numerous studi...

the paper presents results of experimental studies on the methane and propane ignition process in various volumetric compositions of oxidizers heated to temperatures higher than ignition point of analyzed fuels (htac conditions–high temperature air combustion conditions). the increment of temperature dt and the ignition delay time tig are parameters characterizing the process of ignition under ...

Air path control of a spark ignition engine without an EGR loop, equipped with variable-valve-timing (VVT) actuators, is addressed in this paper. VVT devices are used to produce internal exhaust gas recirculation, providing beneficial effects in terms of fuel consumption and pollutant emissions reduction. However, VVT actuators affect the fresh air charge in the cylinders. This has an impact on...

ABSTRACT Stringent NOx and particulate emission constraints require high levels of exhaust gas recirculation. In this paper we model and analyze a Variable Valve Timing methodology that in steady-state achieves large levels of internal Exhaust Gas Recirculation (iEGR) or residual charge in Compression Ignition Direct Injection (CIDI) engines. Current external Exhaust Gas Recirculation (eEGR) te...

The ignition delay times of methane/air mixture diluted by N2 and CO2 were experimentally measured in a chemical shock tube. The experiments were performed over the temperature range of 1300-2100 K, pressure range of 0.1-1.0 MPa, equivalence ratio range of 0.5-2.0 and for the dilution coefficients of 0%, 20% and 50%. The results suggest that a linear relationship exists between the reciprocal o...

Ignition and propagation of a reaction front in a counterflow system of an iso-octane/air stream mixing with an exhaust gas stream is computationally investigated to understand the fundamental characteristics of homogeneous charge compression ignition (HCCI) auto-ignition. Various mixing rates are imposed on the system and the effects of dissipation rates on auto-ignition are studied. Ignition ...

Non-equilibrium plasmas may be used to dissociate reactants into radicals. In turn, these radicals react releasing energy and broadening the radical pool and thereby ignite or aid the ignition of a fuel=air mixture. Using methane as an archetypical fuel, this work studies the kinetic pathways that control homogeneous ignition in the presence of radicals, which were previously formed by external...

In this study, we investigate the effect of different split injection strategies on ignition delay time (IDT) and heat release rate (HRR) characteristics in Reactivity Controlled Compression Ignition conditions via large-eddy simulation finite-rate chemistry. A diesel surrogate (n-dodecane) is injected into a domain with premixed methane oxidiser two separate pulses. Three are investigated by f...