CMC 모델을 이용한 정적 연소실의 디젤 분무 해석

Abstract

A understanding of the dominant physical and chemical phenomena characterizing diesel spray combustion remains the fundamental prerequisite to improve present technology towards more efficient engines. To this end, fundamental studies at constant volume conditions are still essential to evaluate the effects of different fuels, ambient conditions and operating conditions on ambient composition, combustion processes. Engine Combustion Network (ECN) experimental data is useful to validate model implementation because of the wide range of conditions employed. To reduce mesh dependence, gas jet spray model is adopted and implemented into open source code. In this paper both non reacting and reacting condition for n-heptane were validated. The gas jet spray model verified with experimental data of liquid and vapor penetrations. The effects of various ambient oxygen concentration, density and temperature in a high pressure constant volume vessel were predicted. The combustion model is based on conditional moment closure(CMC) and compared with partially stirred reactor(PaSR). Sieser skeletal mechanism performs relatively better than Patel chemistry mechanism. Lift off length results show acceptable agreement in comparison with experimental value, while predicted ignition delay time shows acceptable trends.