Detailed validation for Large Eddy Simulations of the flow field in the valve seat region

We are testing the ability of large eddy simulation (LES) to accurately predict the flow field in the valve seat region of a spark ignition engine. Multi-cycle simulations were carried out with OpenFOAM on moving, body-fitted grids with a mapping approach. LES is a state of the art tool for simulating turbulent flows, and can be applied to engineering applications, e.g. to study cycle-to-cycle variations (CCV) in spark ignition engines. Our simulations are compared against experimental data from Magnetic Resonance Velocimetry (MRV) and Particle Image Velocimetry (PIV). PIV measurements from an optical engine were provided by the group of Prof. Dreizler and MRV data of a 1:1 scaled model of the corresponding engine by Freudenhammer et al. The MRV offers full 3D flow data in the upper part of the combustion chamber, thus allows for the comparison of 3D simulation data to measurements from the valve seat area, which is normally very hard to access experimentally. The results of both measurement techniques are in good agreement with the 3D-LES simulations.