二冲程自由活塞发动机回流扫气仿真研究  

Simulation Study on Loop Scavenging of Two-Stroke Free Piston Engine

作　　者：谭宇航 曹兵[1] 李世金 刘斌 陆俊[1] 刘浩 TAN Yuhang;CAO Bing;LI Shijin;LIU Bin;LU Jun;LIU Hao(School of Mechanical Engineering,Nanjing University of Science and Technology,Nanjing Jiangsu,210094,China)

机构地区：[1]南京理工大学机械工程学院,江苏南京210094

出　　处：《小型内燃机与车辆技术》2024年第6期1-5,38,共6页Small Internal Combustion Engine and Vehicle Technique

摘　　要：以回流扫气式二冲程自由活塞发动机为研究对象,利用CONVERGE软件建立二冲程自由活塞发动机进排气过程的三维计算流体动力学仿真模型,通过改变扫气口仰角和平射角结构参数,分析研究缸内气体流动情况,对比扫气口不同角度参数下的扫气品质。仿真结果表明:当扫气口仰角增大时,气流轴向流量和速度大,短路损失减小,新鲜充量不够集中向四周扩散较快,扫气效率小幅度减小。平射角增大时,短路损失增大,回流扫气特性减弱,扫气效率小范围内呈现先增大后减小的趋势。A three-dimensional computational fluid dynamics(CFD)simulation model of the intake and exhaust process of a loop scavenging two-stroke free piston engine is established by using CONVERGE software,and the gas flow in the cylinder is analyzed and studied by changing the angle of elevation and the angle of ejection of the sweep port.The quality of the swept gas is compared with that of the swept gas under different angular parameters.The simulation results show that when the elevation angle of the sweep port increases,the axial flow and velocity of the gas flow are large,the short-circuit loss is reduced,the fresh charge is not concentrated enough and spreads around faster,and the scavenging efficiency decreases slightly.When the flat shooting angle increases,the short-circuit loss increases,the return flow scavenging characteristic weakens,and the scavenging efficiency shows a trend of first increasing and then decreasing in a small range.

关 键 词：二冲程自由活塞发动机 回流扫气 气口结构参数 数值模拟 

分 类 号：TK413.6[动力工程及工程热物理—动力机械及工程]