연료분무 및 연소 1 : 디젤 분무의 증발 / 비증발 특성 비교 = Fuel Injection and Combustion 1 : Comparison of diesel spray characteristics in non-evaporating / evaporating condition

다국어 초록 (Multilingual Abstract)

Diesel spray is a main phenomenon in a CI (compression ignition) engine. It is important to understand diesel spray characteristics inside the cylinder to design CI engines. Diesel fuel is directly injected into the cylinder by injectors in almost all CI engine. Diesel spray characteristics, such as liquid penetration length, spray angle and vapor distribution, directly affect combustion characteristics and these determine engine performance and emissions. Many researchers are studying fuel spray with experimental and numerical method. CFD method is one of the useful numerical tools to investigate internal combustion engines, recently. Many spray sub-models are derived to simulate fuel spray. Breakup models, evaporation models, collision models and wall-impingement models are included spray sub-models. To describe spray structure properly, it is important to use suitable spray sub-models in CFD code. In this study, diesel spray structure was calculated using OpenFOAM, which is a CFD package coded with C++ language. Kelvin-Helmholtz/Rayleigh-Taylor breakup model, standard evaporation model and O`Rourke collision model were used as spray sub-models to compare diesel spray characteristics in non-evaporating and evaporating condition inside the constant volume chamber. Evaporation model used in spray simulation is important to calculate liquid and vapor distribution inside the constant chamber. Calculated liquid length without evaporation model was less than those with evaporation model. Liquid length of spray was calculated accurately with evaporation model. Droplet sizes with evaporation model were slightly less than those without evaporation model. Evaporation model should be considered to simulate diesel spray even in non-evaporating condition.