船用二冲程柴油机扫气过程流场仿真研究  

Simulation Study on Flow Field of Scavenging Processes of A Two-Stroke Marine Diesel Engine

作　　者：孙志铎 李明坤 常鹏 景晓军 吴春玲 SUN Zhiduo;LI Mingkun;CHANG Peng;JING Xiaojun;WU Chunling(CATARC Automotive Test Center(Tianjin)Co.,Ltd.,Tianjin 300300,China;School of Mechanical Engineering,Tianjin University,Tianjin 300072,China)

机构地区：[1]中汽研汽车检验中心(天津)有限公司,天津300300 [2]天津大学机械工程学院,天津300072

出　　处：《内燃机工程》2023年第6期54-61,共8页Chinese Internal Combustion Engine Engineering

基　　金：国家重点研发计划项目(2022YFC3703600)。

摘　　要：利用三维计算流体力学(computational fluid dynamics,CFD)仿真软件,用数值模拟的方法研究了某型二冲程船用柴油机在不同扫气口仰角与径向倾角下的扫气过程,得到了扫气过程中各时刻气缸内气体的速度矢量图与废气浓度分布图,分析了不同扫气口径向倾角与仰角对扫气过程效果的影响。结果表明:扫气口径向倾角增大时,涡流比增大,气缸中心处废气清扫效果变差,而缸壁附近处废气清扫效果变好;径向倾角较小时情况则与之相反。扫气口仰角增大时,涡流比基本不变,吹扫活塞凹坑处废气效果变差,但整体扫气效率升高。Through numerical simulation using three-dimensional computational fluid dynamics(CFD)software,the scavenging processes of two-stroke marine diesel engine in situations of varying radial inclinations and elevation angles of scavenging ports were studied.Charts about flow field velocity vector and exhaust concentration distribution in cylinders were obtained.The influences of different radial inclinations and elevation angles on the scavenging processes were analyzed.The research results show that when the inclination in radial of scavenging port increases,the swirl ratio increases.The exhaust scavenging effect in the cylinder center gets worse,while the scavenging effect near the cylinder wall is improved.The simulation results of small inclinations are the opposite.When the elevation angle increases,the swirl ratio keeps unchanged.And the exhaust scavenging effect in the pit at top of the piston gets worse,while the overall scavenging efficiency is improved.

关 键 词：柴油机 扫气过程 扫气口 数值模拟 

分 类 号：TK427[动力工程及工程热物理—动力机械及工程]