Large Eddy Simulation of a Motored Single-Cylinder Piston Engine: Numerical Strategies and Validation

International audienceThis paper describes a compressible Large Eddy Simulation (LES) usedto investigate cyclic variations for nonreacting flow in an optical single cylinder engine setup. The simulated operating point is part of a large experimentaldatabase designed to validate LES for cycle-to-cycle prediction, and constitutesa first step towards the realization of fired operating points. The computationaldomain covers almost the whole experimental setup (intake and exhaust plenums,intake and exhaust ducts, cylinder) to account for acoustic phenomena. The assessment of the computation is performed in two regions of the domain: the intakeand exhaust duct predictions are compared to the results of a Helmholtz solver andthe experiment (pressure transducers and Particle Image Velocimetry (PIV)) whilethe in-cylinder dynamics are confronted to PIV measurements. The ability of thedeveloped methodology to capture the correct level of cycle-to-cycle variations is demonstrated considering in-cylinder pressure and velocity fields predictions.Cycle-to-cycle variations in velocity are highlighted and localized using a properorthogonal decomposition analysis