Understanding the behavior of large scale structures in highly Scalable Spectral element simulations of Internal Combustion Engines in the framework of large eddy simulation

In this talk, we investigate the large scale structures generated in various flow regimes (intake, compression, expansion, and~exhaust strokes) of a motored, TCC-III internal combustion (IC) engine. The study is performed with a highly scalable spectral element code Nek5000. The moving boundary problem corresponding to the valves and piston motion are incorporated through a spectrally accurate arbitrary Lagrangian-Eulerian methodology. To avoid severe mesh distortions, we use a novel methodology of interpolating simulation data to a redesigned mesh in-situ, thereby keeping the shape topology of the meshes in control during the simulations. We also use a novel overset-grid methodology to mesh the spark plug region separately in order to reduce re-meshing of the spark region and maintain stability in our simulations. Such high fidelity studies are not only crucial for understanding the multiscale engine-flow dynamics and cyclic variability of the flow features, but also serves as an efficient guideline for developing more advanced models, like species reaction, and spray injection corresponding to realistic IC engines.