LES analysis of turbulent flow and heat transfer in motored engines with various SGS models

This paper presents the application of three different subgrid-scale (SGS) models in a large eddy simulation (LES) for investigating the turbulent flow field and wall heat transfer during the compression–expansion strokes in two types of engine configuration under realistic engine conditions. Predictions were compared with experimental measurements (including the local heat flux and swirl velocity), and with those calculated from the conventional K–ε model. The results of the Van Driest wall damping model for LES were found to be in the best agreement with experimental data. The variations of velocity vector plots, isothermal profiles with crank angle were realized in the “Pancake” chamber engine. The variation of squish strength in the cylinder was also investigated by illustrating the friction velocity variations at different radial locations in the “Deep Bowl Piston” engine.