Computational study of a two-stroke direct-injection reactivity-controlled compression ignition engine:

Reactivity-controlled compression ignition combustion has proved to be effective in reducing the pollutant emissions and the fuel consumption in four-stroke internal-combustion engines. The application of this combustion mode to port-controlled crankcase-scavenged two-stroke engines also seems promising to avoid short-circuiting of fresh charge and to take advantage of the intrinsic residual exhaust gas. Accordingly, a computational study of a small-bore two-stroke dual-fuel direct-injection reactivity-controlled compression ignition engine was made including computational fluid dynamics simulations and zero-dimensional modeling. The zero-dimensional model is used to supply suitable initial conditions for the computational fluid dynamics simulations and to generate useful operating maps. These maps predict the engine behavior, highlighting the conditions where combustion would be controllable by means of in-cylinder reactivity stratification. The computational fluid dynamics simulations were validated aga...