A new turbulent, premixed, stagnation swirl flame (SSF) is used to synthesize titanium dioxide (TiO2) nanopowders. Synthesis conditions under two flame modes, i.e., burnerand substrate-stabilized SSF, are investigated, for the same equivalence ratio, but different inert-dilution ratios. The particles (collected on the substrate) have high anatase purity, with mean diameters of 5–10 nm, determin...

homogenous charge compression ignition (hcci) combustion is spontaneous multi-site combustion of a nominally premixed air/fuel mixture that exhibits high rate of pressure rise and short combustion duration. to avoid excessive pressure rise rate and knocking, hcci engines are fueled with highly diluted mixture using a combination of excess air and/or egr. hcci combustion is attractive due to ext...

This study discusses the design of a new experimental platform, the Hybrid Flame Analyzer (HFA) to measure burning velocity of gas, dust, and hybrid (gas and dust) premixed flames. The HFA is used to analyze a particle–gas–air system of coal dust particles (75–90 lm and 106–120 lm) in a premixed CH4–air (/g = 0.8, 1.0 and 1.2) flame. Experimental results show that particles usually increase the...

In this paper we investigate the properties and linear stability of travelling premixed combustion waves and the formation of pulsating combustion waves in a model with two-step chain-branching reaction mechanism. These calculations are undertaken in the adiabatic limit, in one spatial dimension and for the case of arbitrary Lewis numbers for fuel and radicals. It is shown that the Lewis number...

Mesoscale internal combustion engines for a variety of new combustion system applications have dimensions that are far smaller than conventional macroscale engines, yet unlike true microscale engines allow significant mean flow and turbulence to be created in the combustion chamber by the injection process. The resulting flow allows minimization of the combustion time by augmenting flame propag...

Premixed flames encounter gradients of mixture equivalence ratio in stratified charge engines, lean premixed gas-turbine engines, and a variety of other applications. In cases for which the scales—spatial or temporal—of fuel concentration gradients in the reactants are comparable to flame scales, changes in burning rate, flammability limits, and flame structure have been observed. This paper us...

Gasoline compression ignition (GCI) has been shown as one of the advanced combustion concepts that could potentially provide a pathway to achieve cleaner and more efficient combustion engines. Fuel and air in GCI are not fully premixed compared to homogeneous charge compression ignition (HCCI), which is a completely kinetic-controlled combustion system. Therefore, the combustion phasing can be ...

This is Part II of a series of three papers which jointly address the combustion chemistry of furan and its alkylated derivatives 2-methylfuran (MF) and 2,5-dimethylfuran (DMF) under premixed low-pressure flame conditions. Some of them are considered to be promising biofuels. With furan as a common basis studied in Part I of this series, the present paper addresses two laminar premixed low-pres...

Recent computational studies have simulated a mode of distributed premixed combustion where turbulent mixing plays a significant role in the transport of mass and heat near the reaction zone. Under these conditions, molecular transport processes play a correspondingly smaller role. A consequence of burning in this regime is that a change in the gas mixture composition can occur within the flame...

We consider the grid resolution necessary to resolve combustion in a mixture of calorically imperfect ideal gases described by detailed kinetics and multicomponent transport. Using the steady premixed laminar flame as a paradigm, the required spatial discretization to capture all detailed physics in the reaction zone is found via 1) determination of the finest grid used in a standard software t...