进排气结构参数对微型自由活塞发动机扫气过程影响的数值模拟研究  

Numerical Simulation Study on the Influence of Intake and Exhaust Structure Parameters on Scavenging Process of Micro Free-Piston Engine

作　　者：柏金[1] 孙思楠 王谦[1] BAI Jin;SUN Sinan;WANG Qian(School of Energy and Power Engineering,Jiangsu University,Zhenjiang 212000,China)

机构地区：[1]江苏大学能源与动力工程学院,镇江212000

出　　处：《内燃机工程》2021年第5期42-51,共10页Chinese Internal Combustion Engine Engineering

基　　金：国家自然科学基金面上项目(51876083);江苏大学高级人才科研启动基金项目(14JDG146)。

摘　　要：在微型自由活塞动力装置单缸压燃的研究下,结合单次冲击燃烧可视化试验,针对简化模型的进排气口间距L、进气道倾角α、排气道倾角β,进气道孔径D_(in)及排气道孔径D_(out)展开数值模拟计算以应用于双气缸研究中,使整个运行工况更加平稳且高效。当进、排气口间距不断增大,其换气过程的扫气效率逐渐下降;进气口与排气口的扫气角成一定夹角时,在燃烧室内形成气流涡旋,可以提高其扫气效率。当进气道、排气道孔径不断增大时,扫气效率呈现先上升后下降的趋势,也进一步说明孔径对其扫气过程有明显影响。分析表明进排气结构最佳设计尺寸为:进排气口间距1.0 mm,进气道倾角30°,排气道倾角60°,进气道孔径0.5 mm,排气道孔径0.6 mm,该设计尺寸为研究微型自由活塞发动机双气缸换气过程做了理论铺垫。Based on the study of single-cylinder compression ignition of the miniature free-piston power plant,combined with the single-impact combustion visualization test,the simplified model s intake and exhaust port distance L,intake port angleα,exhaust port angleβ,intake port diameter D_(in) and exhaust port diameter D_(out) were used in the dual-cylinders research to perform numerical simulation calculations,making the entire operating conditions more stable and efficient.When the distance between intake and exhaust ports increases,the scavenging efficiency of air exchange process decreases gradually.At the same time,when the scavenging angle of the intake and exhaust ports becomes a certain angle,an airflow vortex is formed in the combustion chamber,which can improve the scavenging efficiency.When the intake and exhaust diameters continue to increase,the scavenging efficiency will increase first and then decrease,which further shows that the diameters have a significant impact on the scavenging process.The analysis shows that the optimal design size of the intake and exhaust structure are L=1 mm,α=30°,β=60°,D_(in)=0.5 mm,and D_(out)=0.6 mm.This design size has laid a theoretical foundation for studying the air exchange process of the two-cylinder micro free-piston engine.

关 键 词：微型自由活塞发动机 扫气过程 扫气效率 进排气结构参数 

分 类 号：TK431[动力工程及工程热物理—动力机械及工程]