Engine knock is an undesired phenomenon in spark ignited internal combustion engines; such as a gasoline engine running the Otto cycle. Knocking originates from abnormal combustions at timings other than those decided by controlled ignition. Individual abnormal combustions of this type is also referred to as auto-ignition. Knocking is not only a limitation on engine efficiency and thus of envir...

The periodic flame flashback phenomenon in an ethylene-fueled cavity-based scramjet combustor was numerically investigated by a three-dimensional unsteady Reynolds-averaged Navier–Stokes solver with two-step kinetics. air inflow stagnation temperature is 1225 K, and its Mach number 2.6. Spectral analyses revealed the combustion oscillations flashbacks maintained separated mode establishment/van...

Phenol is a product of combustion of coal wood and municipal solid waste; therefore, residents near coal and petroleum fueled facilities as well as residents near municipal waste incinerators may have increased exposure to phenol. Phenol is also a product of auto exhaust, and therefore, areas of high traffic likely contain increased levels of phenol. Recent data on concentrations of phenol in a...

Calcium phosphate [single-phase hydroxyapatite (HA), single-phase tricalcium phosphate (TCP), and biphasic HA-TCP] nanowhiskers and/or powders were produced by using a novel microwave-assisted “combustion synthesis (auto ignition)/molten salt synthesis” hybrid route. This work is an example of our “synergistic processing” philosophy combining these three technologies while taking advantage of t...

The prediction of the auto-ignition delay time of fresh fuel in hot air is studied. This problem, encountered in many combustion systems, is in practice often calculated using a simple method, hereafter called homogeneous mixing ignition (HMI). This method however neglects transport effects and calculates local instead of global ignition properties. A second method is therefore studied called l...

1 WordNet In 1978, George Miller started the development of a database with conceptual relations, as an implementation of a model of the mental lexicon. The database, called WordNet, was organized around the notion of a synset between which semantic relations are expressed. A synset is a set of words with the same part-of-speech that can be interchanged in a certain context. For example, {car; ...

Structural, vibrational and microwave dielectric properties of Nickel-Copper-Zinc ferrite (Ni0.2CuxZn0.8−xFe2O4) ceramics have been presented in this paper. Samples have been prepared using conventional auto-combustion method. The X-ray diffraction (XRD) results confirmed the ferrite samples to be of cubic spinel structure, which further was validated by Fourier transform infrared (FT-IR) and R...

In this paper the large eddy simulation (LES) and conditional moment closure (CMC) combustion model have been applied for modelling of auto-ignition of hydrogen jet issuing into a hot ambient co-flow. Most of the attention was devoted to modelling aspects of the conditional scalar dissipation rate which is a key quantity of the CMC model. Two models are compared with emphasis on differences in ...

This work presents two advances to the estimation of homogeneous charge compression ignition (HCCI) dynamics. Combustion phasing prediction in control-oriented models has been achieved by modeling the in-cylinder temperature and composition dynamics, which are dictated by the large mass of residuals trapped between cycles. As such, an accurate prediction of the residual gas fraction as a functi...