Internal combustion engine flows for motored operation

Application Area 2: Combustion

Application Challenge AC2-10

Abstract

This test case provides data on the in-cylinder flow for an IC engine under motored operation. The Technische Universität Darmstadt engine features a typically design of a modern spark-ignition direct injection engine. It is an optically accessible single cylinder engine especially designed to provide well characterized boundary conditions and reproducible engine operation; a prerequisite for any comparison of experiments and simulations. The in-cylinder flow is characterized by various particle image velocimetry (PIV) techniques to provide measurements at high spatial and temporal resolutions. The database for validation includes the first two statistical moments (mean and rms) of velocities, spatial flow structures and the temporal evolution of the flow field over the entire engine cycle in the central tumble plane. Information on the 3D flow is available within a volume up to 8 mm thick centered on the central tumble plane. Important boundary conditions as the in-cylinder, intake- and exhaust-port pressures as well as temperatures are given. Simulation results obtained from three investigations using LES (Large Eddy Simulation) and hybrid URANS (unsteady Reynolds-averaged Navier-Stokes)/LES are presented and compared with the experimental results.