Large Eddy Simulation of Direct Injection Processes for Hydrogen and LTC Engine Applications 2008-01-0939
Direct injection (DI) has proven to be a promising option in Diesel and low temperature combustion engines. In conventional Diesel and homogeneous charge compression ignition (HCCI) applications, DI lowers soot and NOx production and improves fuel economy. In hydrogen fueled engines, DI provides the appropriate energy density required for high efficiency and low NOx emissions. To realize the full benefit of DI, however, the effect of various injection parameters, such as injection timing, duration, pressure, and dilution, must be investigated and optimized under a range of engine operating conditions. In this work, we have developed a model for high-fidelity calculations of DI processes using the Large Eddy Simulation (LES) technique and an advanced property evaluation scheme. Calculations were performed using an idealized domain to establish a baseline level of validation. The theoretical-numerical framework combines a general treatment of the governing conservation and state equations with state-of-the-art numerical algorithms and massively-parallel programming paradigms. This software enables both the canonical cases described here and in-cylinder calculations. Here we focus on high-pressure multi-port gas injectors designed for application in hydrogen-fueled IC-engines. This study was conducted in support of a larger effort to perform detailed in-cylinder LES calculations of companion optical engine experiments.