Large-Eddy Simulation of in-Cylinder Flows

Advances in physical models, numerical methods, and computational power together have brought large-eddy simulation (LES) to the point where it warrants serious consideration for computing in-cylinder turbulent flows. This article includes: a discussion of LES and how it differs from Reynolds-averaged Navier Stokes (RANS) modeling; motivation for transitioning to LES for in-cylinder flow in IC engines; and quantitative results for two motored engine configurations. Dynamicsubgrid-scale stress models are emphasized, and results from two different numerical approaches are discussed. Compared to RANS, LES requires a low level of empirical input, provides more complete information on in-cylinder flow structure, and makes previously inaccessible phenomena (e. g. , cycle-to-cycle variability) amenable to analysis