ID#: 158
Abstract Title: Three-Dimensional Modeling of DI Diesel Engine Combustion using a Flamelet Concept
Session Title: Reciprocating Engines
Session Date: 7/31/01
Session Start Time: 2:00 PM
Contributing Author: Hasse, C.
Organization: ITM, RWTH Aachen
Country: Germany
Authors: Christian Hasse, Norbert Peters
Short Abstract: Numerical simulation of diesel engine combustion has become an important tool in engine development. One major issue in modeling of turbulent reactive flows is the interaction of turbulence and chemistry. One successful way to model this interaction is the use of the Representative Interactive Flamelet (RIF) model. The RIF model describes all phases of diesel engine combustion and therefore there is no need to use separate submodels for ignition or diffusive burning. It allows to use detailed reaction schemes which include submechanisms for all major pollutants such as NOx or soot. The RIF model has been recently extended to a multiple flamelet model which is called Eulerian Particle Flamelet Model (EPFM). Each representative flamelet is represented by an eulerian particle having its own time history. These particles are convected through the flow field and an equation for the probability of finding a particle at a certain location and time has been derived on the basis of a Pdf transport equation. Using multiple flamelets allows to account for spatial variations of the scalar dissipation rate which is especially important during the ignition phase. We present results for a direct injection diesel engine. In addition to a general discussion we focus on various new aspects of interest which include the homogenization of the flow field and its effect on transport processes in the flamlet and the effect of vaporization in the balance equation of the mixture variance which shows to have an important effect on the scalar dissipation rate.