Computation of mixing processes related to EGR

Authors: Sakowitz, A.S., Fuchs, L.F.
Document Type: Conference
Pubstate: Published
Journal: Proceedings of the 7th International Symposium on Turbulence and Shear Flow Phenomena, 28-31 July 2011, Ottawa, Canada
Year: 2011


Turbulent mixing processes related to the application of exhaust gas recirculation (EGR) in internal combustion engines are investigated using different turbulence models, i.e. RANS and LES. First, the mixing process in a simplified geometry, a T-junction with circular cross-sections, is considered under steady and pulsating in-flow conditions. The focus lies on the evaluation of the applied models and their effect on the mixing under the given flow conditions. The same turbulence models are then applied to a Diesel engine inlet manifold. It is shown that the EGR distribution to the different cylinders is non-uniform and hence affecting the total emissions from the engine. The non-uniformity of the EGR concentration implies also that the smoothing effect of the URANS model may not be adequate for determining the local temporal- and spatial-EGR distribution at the cylinder intakes.