The demand for better understanding of the mechanism of soot formation is driven by the negative environmental and health impact brought about by the burning of fossil fuels. While soot particles accumulate most of their mass from surface reactions, the mechanism for surface growth has so far been characterized primarily by measurements of the kinetics. Here we provide atomic-scale scanning tun...

Comparisons between numerical results and experimental data for a homogeneous charge compression ignition (HCCI) engine with optical accessibility are being presented in this paper. The KIVA – 3V program, a general purpose combustion routine, is being enhanced by implementing the optimized Shell model for the ignition process, applying the extended Zeldovich formulation for nitrogen oxide forma...

A new Monte Carlo method termed Comb-like frame Monte Carlo is developed to simulate the soot dynamics. Detailed stochastic error analysis is provided. Comb-like frame Monte Carlo is coupled with the gas phase solver Chemkin II to simulate soot formation in a 1-D premixed burner stabilized flame. The simulated soot number density, volume fraction, and particle size distribution all agree well w...

Introduction Diesel soot elimination is a very difficult problem. The catalytic filters seems to be one of the technological alternatives in order to trap and burn the soot, at the exhaust gas temperature. In order to advance in a rational catalyst design, the reaction mechanism must be understood. In spite of this need, and even though there are many papers in the field, detailed studies regar...

We use the numerically exact superposition T-matrix method to compute the optical cross sections and the Stokes scattering matrix for polydisperse mineral aerosols (modeled as homogeneous spheres) covered with a large number of much smaller soot particles. These results are compared with the Lorenz-Mie results for a uniform external mixture of mineral and soot aerosols. We show that the effect ...

Ways to reduce nitrogen oxide emissions One of MTU ś aims for its engines is to reduce the emission of soot particles and nitrogen oxides in order to achieve compliance with increasingly strict emissions regulations around the world. The main approach pursued by MTU is low-emission combustion, in other words an internal engine solution. However, this means taking into account a basic principle ...

The analysis of soot formation and oxidation is essential for Diesel engine development to meet future pollutant emission reduction requirements. In recent years laser-induced incandescence (LII) has developed to a powerful tool for soot diagnostics in flames, even in the challenging environment of Diesel combustion. This work presents some recent applications of LII for soot particle sizing in...

The growth of hydrocarbon molecules up to sizes of incipient soot is computed in premixed laminar flames using kinetic Monte Carlo and molecular dynamic methodologies (AMPI code). This approach is designed to preserve atomistic scale structure (bonds, bond angles, dihedral angles) as soot precursors evolve into three-dimensional structures. Application of this code to aliphatic (acetylene) and ...

The dimensions of graphitic layer planes directly affect the reactivity of soot towards oxidation and growth. Quantification of graphitic structure could be used to develop and test correlations between the soot nanostructure and its reactivity. Based upon transmission electron microscopy images, this paper provides a demonstration of the robustness of a fringe image analysis code for determini...

A new experimental method has been developed to conduct surface chemistry and extract surface kinetic rates on size-selected nanoparticles. The method utilizes a tandem differential mobility analyzer (TDMA) technique in which monodisperse particles are selected from a polydisperse aerosol input stream and then subjected to chemical processing. The change in particle size is measured and used to...