Detailed Spark Ignition Modelling applied to Compressed Natural Gas Engines

Autor: Gunesh Tallu

ISBN: 978-3-95900-757-3

Dissertation, Leibniz Universität Hannover, 2022

Herausgeber der Reihe: Friedrich Dinkelacker

Band-Nr.: ITV 02/2022

Umfang: 188 Seiten, 75 Abbildungen

Schlagworte: Natural gas engines, 3D CFD simulation, Spark ignition modelling

Kurzfassung: For compressed natural gas engines, the ignition and combustion processes need particular attention. In this work, an advanced spark ignition model is developed for application in the three-dimensional Computational Fluid Dynamics (3D CFD) simulation. Here the flame kernel development is modelled with chemical heat released by the air-fuel mixture and spark ignition parameters. Pre-calculated libraries of thermo-kinetic properties are used to couple detailed chemical kinetic mechanisms with this model. A cluster of Lagrangian particles caters to the effects of turbulence on flame kernel movement. The consecutive flame propagation is modelled with the G-Equation level set approach.
Extensive validation of this model is carried out with experiments spanning from a constant volume chamber, a rapid compression machine and a transparent engine to serial engines with open chamber and with lean prechamber spark ignition. The model is applied for broadly varied boundary conditions, including ultra-lean mixtures. With the help of different calculated parameters, this model can also predict rare events like a misfire and restrike beforehand.