A three-dimensional reacting flow modeling approach is presented for diesel engine studies that can be used for predictions of trends in soot emissions for a wide range of operating conditions. The modeling framework employs skeletal chemistry for n-heptane for ignition and combustion, and links acetylene chemistry to the soot nucleation process. The soot model is based on integration and modif...

We summarize our current research on combustion aerosols. First, sampling devices for the analyses of flame gases are described. The flame gas samples are investigated by mass spectroscopy and by standard aerosol techniques. Time-of-flight mass spectroscopy is well suited to study formation and growth of soot precursor molecules. Fullerenes can also be seen in some mass spectra of flame gases. ...

A technique of computing the pressure drop and deposition rate evolution during soot loading and the 3D distribution of deposited soot particles for micro-structured ceramic filter media is presented. Methods developed at Fraunhofer ITWM for generating 3D computer models representing the microstructure of the filter material and for computing soot particle deposition in the microstructure model...

Carbonaceous soot produced in a small diesel engine test facility was investigated with ultra-small-angle X-ray scattering. Three soot samples produced using a reference diesel fuel and the reference fuel plus two oxygenate additives were investigated. The presence of objects at three typical size ranges, i.e., aggregates, primary particles, and subunits, was observed. By studying soot powders ...

The scalar structure of the overfire (fuel-lean) region of sooting turbulent diffusion flames was investigated, considering ethylene and acetylene burning in air. Measurements and predictions are reported of the mean concentrations of major gas species and mean soot volume fractions. Predictions were based on the conserved-scaiar formalism in conjunction with the laminar flamelet approximation....

Soot concentrations are generally over predicted during the typical application of fire models. The addition of soot deposition and gravitational settling mechanisms to Fire Dynamics Simulator (FDS) results in improved predictions; however, those predictions are highly dependent upon assumptions of soot particle size. Large particle sizes appear to be needed to get FDS predictions on soot conce...

The development of a cascaded feedback control strategy for a vapor-phase axial deposition (VAD) process is investigated in this paper. VAD is a widely used process in the creation of high purity glass for optical fiber. In previous work a soot tip surface temperature controller was developed for the VAD process to reduce the effects of core soot temperature variation on deposition, leading to ...

In this work we present a numerical iterative procedure for the evaluation of the effect of signal absorption in two-color laser-induced incandescence (2C-LII) measurements. The correction process is applied to experimental results, previously published by our group, in an axisymmetric diffusion flame. We have studied the influence of signal trapping on peak soot temperature and on soot volume ...

The purpose of this paper is to address the differences observed in the oxidative kinetics between flame and diesel derived soots. In particular, it has been observed that flame soot has a significantly higher activation energy for oxidation than does diesel soot. The hypothesis tested in this paper is that metals, possibly coming from lubricating oils, within diesel generated soot particles ma...

Several series of chronic experiments in white mice and white rats were carried out in order to determine the carcinogenicity of Estonian oil shale soot as well as the soot from oil shale fuel oil. All the investigated samples of soot showed a relatively low (from 14 to 1200 ppm) benzo(a)pyrene content. The benzene extract of oil shale soot, painted on the skin of white mice, proved to be stron...