Köpple, F., Jochmann, P., Kufferath, A., and Bargende, M., "Investigation of the Parameters Influencing the Spray-Wall Interaction in a GDI Engine - Prerequisite for the Prediction of Particulate Emissions by Numerical Simulation," SAE Int. J. Engines 6(2):911-925, 2013, https://doi.org/10.4271/2013-01-1089.
Due to the EU6 emission standard that will be mandatory starting in September 2014 the particulate emissions of GDI engines come into the focus of development.For this reason, soot and the mechanisms responsible for the soot formation are of particular importance. A very significant source of particulate emissions from engines with gasoline direct injection is the wall film formation. Therefore, the analysis of soot emission sources in the CFD calculation requires a detailed description of the entire underlying model chain, with special emphasis on the spray-wall interaction and the wall film dynamics.The validation of the mentioned spray-wall interaction and wall film models is performed using basic experimental investigations, like the infrared-thermography and fluorescence based measurements conducted at the University of Magdeburg. This comparison demonstrates that the used modeling is not only able to correctly reproduce all trends, but also to do quantitatively correct predictions in most instances.Additionally, on the basis of the measurements carried out on an optically accessible single-cylinder engine, the verification of the presented model chain in an in-cylinder flow simulation is shown. Using a defined multi-component fuel, a good correlation between the calculated mixture formation and the measured particulate emissions is demonstrated.In essence, the scope of this paper is to present a method, which allows a detailed modeling of the spray-wall interaction as well as the wall film dynamics by numerical simulation, throughout the whole parameter space relevant to an engine process.