Technical Paper
Large-Eddy Simulation Study of Biofuel Injection in an Optical Direct Injection Engine
2020-09-15
2020-01-2121
The air-fuel mixture formation in an optical direct-injection internal combustion engine is investigated by numerical simulations for the two biofuels Ethanol and 2-Butanone. The gas phase in the internal combustion (IC) engine is predicted by a large-eddy simulation, in which the fuel phase is determined by a spray model based on Lagrangian particle tracking. A hollow-cone injector is used for which the primary breakup is modeled by a series of small full-cone injections, while the Rosin-Rammler initial droplet size distribution is used. The secondary spray break-up is modeled by the Kelvin-Helmholtz-Rayleigh-Taylor (KHRT) model, and the evaporation of the fuel is determined by the Bellan-Harstad model. The gas phase simulation is based on a finite-volume method formulated for hierarchical Cartesian grids, in which the immersed moving boundaries are resolved using a multiple level-set/cut-cell approach.