Tri-Reactivity Ignition: Simulation and Experiments

Liquified natural gas, being mainly methane, is an attractive clean fuel for marine gas engine applications e.g. in the arctic/coastal regions. However, methane burns poorly in the preferred conditions leading to unwanted cycle-to-cycle variations i.e. strong efficiency fluctuations. Here, methane combustion enhancement via hydrogen addition is investigated for lean, low-temperature gas combustion engine concepts. We aim at finding a quantitative link between ignition-to-ignition variations and cycle-to-cycle variations. The ignition variations are short in duration and investigated via high resolution computational fluid dynamics simulations with a detailed chemistry model in open source code environment. The cycle-to-cycle variations occur on longer time scales and they are studied in optical engine experiments. The project links closely to the International Engine Combustion Network initiative. The results are applicable to LNG and various alternative fuels.