超长冲程低速柴油机换气过程的双区域仿真建模

Two-zone simulation modeling of gas exchange process of super-long-stroke low-speed diesel engine

为了研究船用超长行程二冲程直流扫气柴油机的扫气特性,本文采用以"混合-分层"理论为基础的组合换气模型模拟二冲程柴油机的换气过程,在Matlab/Simulink平台上建立相应的换气过程模型,并对该模型进行了实验验证。利用扫气空气质量流量确定"混合-分层"模型中的比例系数,并根据比例系数计算出船用超长行程低速柴油机的扫气效率等特性参数,研究了不同比例系数对二冲程柴油机换气过程的影响。研究结果表明:本文建立的二冲程柴油机换气过程模型,能精确模拟直流扫气柴油机的换气过程,并结合实验数据预测二冲程柴油机扫气过程的特性参数,为后续整机建模提供基础。

To study the scavenging characteristics of a super-long-stroke,uniflow-scavenging two-stroke uniflow-scavenged diesel engine,this paper presents a combined model based on the"mixed-layered"theory to simulate the gas exchange process of a two-stroke diesel.AnA gas exchange model was established by Matlab/Simulink and then verified by an experiment.The proportional coefficient of the"mixed-layered"model was determined by the mass flow of sweeping air,and then scavenging characteristic parameters,likesuch as the sweeping efficiency of marine super-long-stroke low-speed diesel engine,were calculated according to the proportional coefficient.BesidesIn addition,the influence of different proportional coefficientcoefficients on the gas exchanging process of a two-stroke diesel engine was investigated.ResultThe result shows that the simulation model in this paper can accurately simulate the gas exchanging process of uniflow-scavenged diesel engines,and predict the scavenging characteristics byin combination with the experimental data,whichcan predict the scavenging characteristics;therefore,the study provides thea basis for the subsequent overall engine modelingling.