An Improved Representative Interactive Flamelet Model Accounting for Evaporation Effect in Reaction Space (RIF-ER).

Internal Combustion Engine;Combustion Model;Homogeneous Charge Compression Ignition;Mechanical Engineering;Engineering;Mechanical Engineering

Keum, Seung HwanDriscoll, James F. ;

University of Michigan

关键词: Internal Combustion Engine;    Combustion Model;    Homogeneous Charge Compression Ignition;    Mechanical Engineering;    Engineering;    Mechanical Engineering;   

Others  :  https://deepblue.lib.umich.edu/bitstream/handle/2027.42/62293/sgtkeum_1.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Recently, applications of spray combustion in internal combustion engines (ICE) are beingexpanded from conventional to gasoline direct injection engines. Moreover, stratificationusing spray is further considered as a controlled autoignition (CAI) measure in HomogeneousCharge Compression Ignition (HCCI) engines.A well validated spray combustion model can provide a good modeling tool which canfacilitate understanding of spray combustion physics. In this research, a spray combustionmodel is proposed to model low temperature combustion in internal combustion engines.The proposed model is based on the Representative Interactive Flamelet (RIF) model ofPeters (2000). In addition to the original RIF model, the effect of spray and vaporization ofdroplets in the reaction space were considered to be included in the governing equations assource terms. The effect of such source terms were examined in the reaction space in idealizedcontrol volumes, where the effect of vaporization is assumed as gaseous fuel additionwith known rate of addition. It was found that the effect of spray may not be negligiblewhen fuel addition occurs over a reaction space with chemical reaction. The proposedmodel was validated by comparing pressure and fuel concentration against experimentaldata from the rapid compression machine experiment of Akiyama et al. (1998) and thediesel engine experiment of Hong et al. (2008). Predictions showed good agreement withthe experimental observations. Comparison between numerical models, one with spraysource terms and the other without them has been carried out to examine the effect of spraysource terms on spatial fuel distributions and overall pressure histories.The proposed model has been implemented in KIVA3v. The proposed model is applied to investigate the effect of stratification under PPCI operating condition using direct injection.An experimental study on the effect of stratification on combustion and emission hasbeen numerically reproduced. The numerical results showed good qualitative agreementwith the measured engine performance and emission trend against the experimental data.Detailed analysis of the in–cylinder combustion is also provided.