This research area focusses on the numerical simulation of turbulent, single- and two-phase flows with emphasis on combustion and emission formation at internal combustion engine relevant conditions in the RANS and LES context. Systems of interest encompass engines from passenger car to heavy-duty and marine engine dimensions for current and future combustion modes including spark and pre-chamber ignited premixed, direct-injected spark- and compression-ignition operation, HCCI and dual fuel combustion. Fuels investigated include conventional fossil Diesel/gasoline and corresponding surrogates, methane as well as alternative fuels e.g. oxygenated and biogenic fuels from “power-to-gas” concepts.
Model development and validation is supported by high-fidelity experimental data from optically accessible combustion facilities including high pressure spray rigs, rapid-compression-expansion-machines, a large two-stroke marine engine reference experiment as well as optical engines, installed in-house or in collaboration with external partners and research networks such as the engine combustion network ECN. Emerging Direct Numerical Simulation datasets at engine relevant conditions increasingly provide further insight and support for model development.
Current topics of interest include in particular turbulence-chemistry interaction, soot dynamics and NOx formation in auto-igniting high-pressure sprays; early flame kernel growth, the related cycle-to-cycle variations and the impact on emissions and engine knock in spark ignited engines; pilot spray auto-ignition and the transition to turbulent premixed flame propagation in dual fuel combustion, and, for HCCI, the impact of thermal stratification and fuel composition – especially with respect to oxygenated compounds – on the ignition delay and low- and high temperature heat release.