Simulation of HC-Emissions from SI-Engines - A Parametric Study 972893
Earlier modelling of SI engine HC-emissions indicated that the absorption/desorption of fuel HC in the oil film played a rather important role for the engine-out HC-emissions. However, recent experimental results seem to indicate that this mechanism does not play a major role. Therefore, we updated a previous model in order to obtain a better understanding of the absorption/desorption phenomenon. The upgraded absorption/desorption model has been combined with the MIT ring/liner lubrication model and applied to a single cylinder engine with known lubrication characteristics. The calculations have been carried out for steady-state and warm-up conditions. Compared to earlier results we found that due to an essentially smaller oil film thickness calculated by the lubrication model the absorption/desorption process exhibits a much faster response than previously estimated. The main statement is that the oil film on the cylinder liner is fully penetrated by the absorption /desorption process for warmed-up conditions in the case of ideal lubrication. The importance of this work is that the in-cylinder HC-emissions originating from this HC-emission source are proportional to the total volume of oil contained on the combustion chamber surfaces. This result stresses the importance of further increased oil control for SI-engines. However, the contribution to engine-out HC-emissions is smaller than previously thought due to increased postoxidation of the hydrocarbons emitted from this source.
Citation: Frølund, K. and Schramm, J., "Simulation of HC-Emissions from SI-Engines - A Parametric Study," SAE Technical Paper 972893, 1997, https://doi.org/10.4271/972893. Download Citation
Author(s):
Kent Frølund, Jesper Schramm
Affiliated:
The Technical University of Denmark
Pages: 20
Event:
International Fuels & Lubricants Meeting & Exposition
ISSN:
0148-7191
e-ISSN:
2688-3627
Also in:
Combustion and Emission Formation in SI Engines-SP-1300
Related Topics:
Single cylinder engines
Spark ignition engines
Combustion chambers
Engine lubricants
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