A CFD-based numerical model has been developed for the determination of the volume concentration and number density of soot in a laminar diffusion flame of methane in air, under transient condition following ignition of the flame. The transience is studied from the point of ignition till the final steady state is reached. The burner is an axi-symmetric co-flowing one with the fuel issuing throu...

Detailed modeling of an experimental ethylene/air jet flame is undertaken using the composition PDF method for gas-phase kinetics coupled with detailed models for soot formation and radiation from the flames. The gas-phase kinetics is modeled using a reduced mechanism for ethylene consisting of 33 species and 205 elementary reactions. The soot formation is modeled using the method of moments wi...

The formation of soot particles in combustion depends on several factors that include: pressure, temperature, fuel chemical structure and extent of premixing. An improved version of the thermophoretic particle densitometry (TPD) method, has been used in this study for quantitative and qualitative characterization of soot particles generated in laminar partially-premixed co-flow flames having di...

In this study an expression for soot absorption coefficient is introduced to extend the weighted-sum-of-gray gases data to the furnace medium containing gas-soot mixture in a utility boiler 150 MWe. Heat transfer and temperature distribution of walls and within the furnace space are predicted by zone method technique. Analyses have been done considering both cases of presence and absence of soo...

Although diesel engines have an advantage of low fuel consumption compared with gasoline engines, several problems must be solved. One of the major concerns is that diesel exhaust gas has more particulate matters (PM) including soot, which are suspected to be linked to human carcinogen. As one of the key technologies, a diesel particulate filter (DPF) has been developed to reduce PM in the afte...

The purpose of this work is to propose a detailed model for the formation of soot in turbulent reacting flow and to use this model to study a carbon black furnace. The model is based on a combination of a detailed reaction mechanism to calculate the gas phase chemistry, a detailed kinetic soot model based on the method of moments, and the joint composition probability density function (PDF) of ...

The reaction mechanisms for diesel soot oxidation over V4/ZrO2 or V4/TiO2 oxide catalysts were studied by the means of in-situ UV-Raman spectroscopy. The results indicate that the formation of surface oxygen complexes (SOC) is a key step and the SOC species mainly exist as carboxyl groups. The presence of NO in the reaction gas stream can promote the formation of SOC species. For soot oxidation...

Introduction Conclusions References Tables Figures Back Close Abstract Introduction Conclusions References Tables Figures Back Close Abstract In the present study, the heterogeneous conversion of nitrogen oxide (NO) and nitrogen dioxide (NO 2) was studied at atmospheric humidity levels on flame soot surfaces, which were treated with gaseous nitric acid (HNO 3). In addition, the heterogeneous re...

Major pollutants emission from Direct-Injection (D.I) diesel engines are predicted by means of a mathematical model. In order to construct such a model, an integral Multi-Zone Combustion Model (MZCM) is formulated, which basically consists of jet mixing and combustion submodels. In MZCM, variation of injection pressure is considered. Also time period of ignition delay is predicted by considerin...

Soot volume fraction and number density in a turbulent diffusion flame burning kerosene/air were predicted using two approaches. The first used a conventional soot inception model based on the acetylene concentration and is referred to as the acetylene model. The second used a soot inception model based on the formation rate of three and two ring aromatics [1] and is referred to as the PAH ince...