The dynamics of soot formation in turbulent ethylene–air nonpremixed counterflow flames is studied using direct numerical simulation (DNS) with a semi-empirical soot model and the discrete ordinate method (DOM) as a radiation solver. Transient characteristics of soot behavior are studies by a model problem of flame interaction with turbulence inflow at various intensities. The interaction betwe...

III. Project background: The SERDP statement of need that led to this research project focuses on a requirement for better models of the mechanisms of soot formation in combustion. Soot and its combustion precursors present human health hazards. In the case of Army fighting vehicles, such as those powered by diesel engines, it is of interest to achieve the maximum possible power density. One wa...

The influence of transport properties of inert additives on soot formation in a coflow axisymmetric ethylene/air diffusion flame has been numerically investigated. Detailed reaction mechanism and complex thermal and transport properties were used. The fully coupled elliptic equations were solved. The radiative heat transfer from CO, CO2, H2O, and soot was calculated using the discrete-ordinates...

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...

Simultaneous planar laser-induced incandescence, hydroxyl radical planar laser-induced fluorescence, and droplet Mie scattering are used to study the instantaneous flame structure and soot formation process in an atmospheric pressure, swirl-stabilized, liquid-fueled, model gas-turbine combustor. Optimal excitation and detection schemes to maximize single-shot signals and avoid interferences fro...

The environmental soot and carbon blacks (CBs) cause many diseases in humans, but their underlying mechanisms of toxicity are still poorly understood. Both are formed after the incomplete combustion of hydrocarbons but differ in their constituents and percent carbon contents. For the first time, "Sir Percival Pott" described soot as a carcinogen, which was subsequently confirmed by many others....

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...

The high-energy-density (HED) fuels developed under U.S. Navy sponsorship as a replacement for conventional liquid fuels in its missile propulsion systems have the drawback of high soot propensity: this makes missiles visible and thus strategically unacceptable. Experimental evidence of heavy sooting from such potential fuels has been presented by Law[l]. Soot propensity is defined here as the ...

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 main objective of the work presented in this paper will be to present and discuss the development and implementation of a numerical model to simulate soot formation and depletion in turbulent diffusion flames. The relevance of such model lays on the importance of tying the formation of soot to the ongoing reaction mechanism so that it is fully integrated into the combustion process. The mod...