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Photo Credit: KIT

01.10.2021

MTZ Project Reports: Modeling and Investigation of Particle Formation in DI Gasoline Engines in Transient Driving Situations

The aim is to reduce the number of particles in the engine, but particulate filters must also be designed more efficiently, especially in gasoline engines. Both can only be achieved through a deeper understanding of the processes in the combustion chamber and their model-based simulation. At the Karlsruhe Institute of Technology (KIT) and the Technical University (TU) of Darmstadt, a methodology for simulating the particulate emissions of two gasoline engines under transient conditions was developed in the FVV project Systemic Analysis of Particle Formation on Gasoline Engines (FVV No. 1282).

In previous works, the influence of various engine parameters on the particle behavior of direct injection gasoline engines has already been intensively investigated. The particle behavior and particle sources were analyzed both in steady-state tests on research single-cylinder engines and in load steps on a near-production fullengine [1, 2]. In particular, the significance of areas of inhomogeneous combustion, such as pool flames on the combustion chamber wall and piston could be demonstrated [3].

Due to the RDE legislation, tests on transient driving conditions gain more importance compared to stationary experiments alone. In the research project, which was carried out at the Institute for Piston Engines (IFKM) of the KIT and the Institute for Internal Combustion Engines and Powertrain Systems (VKM) of TU Darmstadt, the focus was therefore on driving conditions critical for particulate emissions that occur during transient engine operation. The particle sources were to be identified and the correlations found were to be mapped by means of a model for the particles numbers.

The research project succeeded in developing and validating a suitable methodology for gasoline engines simulating the particle emission in transient behavior. For this purpose, a parameter study was carried out on two different engines using a special transient test cycle, the MRT. Based on measurements of the particle count as well as identification of soot sources with optical measurement techniques, an empirical model could be built, which represents a good reproduction of the total particle emissions of a test run. In order to build a generally valid model using this methodology, further different engines need to be run evaluated in transient runs with a larger number and variation of parameters.

 

REFERENCES
[1] Dageförde, H.: Untersuchung innermotorischer Einflussgrößen auf die Partikelemission eines Ottomotors mit Direkteinspritzung. Karlsruhe, Karlsruhe Institute of Technology (KIT), dissertation, 2015
[2] Bertsch, M.: Experimental Investigations on Particle Number Emissions from GDI Engines. Karlsruhe, Karlsruhe Institute of Technology (KIT), PhD thesis, 2017
[3] Disch, C.: Untersuchung der Gemischbildung, Verbrennung und Schadstoffentstehung eines Ottomotors mit Direkteinspritzung im transienten Betrieb. Karlsruhe, Karlsruhe, Karlsruhe Institute of Technology (KIT), dissertation, 2017

Project profile

The FVV in the MTZ and ATZ magazine

Results from Industrial Collective Research are accessible to all interested parties and thus final reports of FVV research projects will be presented to the public at our conferences in spring and autumn. In order to further promote the transfer of knowledge and the expansion of the prime movers innovation network, we publish articles on individual projects with particularly interesting new insights in the world's leading specialist magazines for the engine and vehicle industries. MTZ / ATZ and FVV have been working together successfully in this field for many years.

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