Liquid breakup in fuel spray and atomization significantly affects the consequent mixture formation, combustion behavior, and emission formation processes in a direct injection diesel engine. In this paper, different ...Liquid breakup in fuel spray and atomization significantly affects the consequent mixture formation, combustion behavior, and emission formation processes in a direct injection diesel engine. In this paper, different models for liquid breakup processes in high-pressure dense diesel sprays and its impact on multi-dimensional diesel engine simulation have been evaluated against experi- mental observations, along with the influence of the liquid breakup models and the sensitivity of model parameters on diesel sprays and diesel engine simulations. It is found that the modified Kelvin-Helmholtz （KH）-Rayleigh-Taylor （RT） breakup model gives the most reasonable predicted results in both engine simulation and high-pressure diesel spray simulation. For the standard KH-RT model, the model constant Cbl for the breakup length has a significant effect on the predictability of the model, and a fixed value of the constant Cbl cannot provide a satisfactory result for different operation conditions. The Taylor-analogy- breakup （TAB） based models and the RT model do not provide reasonable predictions for the characteristics of high-pressure sprays and simulated engine performance and emissions.展开更多
目前的民机结冰适航规范中,大粒径过冷水滴(supercooled large droplet,SLD)环境尚未得到规定,是一个重大的飞行安全隐患。由于SLD的粒径较大(大于50μm),在研究其结冰时需要考虑水滴动力学过程。针对SLD成冰模拟中破碎模型的不足,根据...目前的民机结冰适航规范中,大粒径过冷水滴(supercooled large droplet,SLD)环境尚未得到规定,是一个重大的飞行安全隐患。由于SLD的粒径较大(大于50μm),在研究其结冰时需要考虑水滴动力学过程。针对SLD成冰模拟中破碎模型的不足,根据对破碎机理的认识提出了多因素破碎(multifactor-effected breakup,MEB)判定模型,并结合积冰算法对SLD环境中的结冰进行了模拟,验证了模型的有效性,证明其能提高对SLD结冰的模拟能力。从翼面收集率及冰型生长两方面对SLD的结冰过程和水滴动力学过程产生的效应进行了分析。展开更多
文摘Liquid breakup in fuel spray and atomization significantly affects the consequent mixture formation, combustion behavior, and emission formation processes in a direct injection diesel engine. In this paper, different models for liquid breakup processes in high-pressure dense diesel sprays and its impact on multi-dimensional diesel engine simulation have been evaluated against experi- mental observations, along with the influence of the liquid breakup models and the sensitivity of model parameters on diesel sprays and diesel engine simulations. It is found that the modified Kelvin-Helmholtz （KH）-Rayleigh-Taylor （RT） breakup model gives the most reasonable predicted results in both engine simulation and high-pressure diesel spray simulation. For the standard KH-RT model, the model constant Cbl for the breakup length has a significant effect on the predictability of the model, and a fixed value of the constant Cbl cannot provide a satisfactory result for different operation conditions. The Taylor-analogy- breakup （TAB） based models and the RT model do not provide reasonable predictions for the characteristics of high-pressure sprays and simulated engine performance and emissions.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.11532015 and U1738119)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘目前的民机结冰适航规范中,大粒径过冷水滴(supercooled large droplet,SLD)环境尚未得到规定,是一个重大的飞行安全隐患。由于SLD的粒径较大(大于50μm),在研究其结冰时需要考虑水滴动力学过程。针对SLD成冰模拟中破碎模型的不足,根据对破碎机理的认识提出了多因素破碎(multifactor-effected breakup,MEB)判定模型,并结合积冰算法对SLD环境中的结冰进行了模拟,验证了模型的有效性,证明其能提高对SLD结冰的模拟能力。从翼面收集率及冰型生长两方面对SLD的结冰过程和水滴动力学过程产生的效应进行了分析。
