{"title":"Influence of key structure of diesel engine helical intake port on intake stratification","authors":"Guangyuan Bao, He Chao, Jiaqiang Li, Xueyuan Liu","doi":"10.1177/09544070241254424","DOIUrl":null,"url":null,"abstract":"In order to control gas stratification in diesel engine cylinders and achieve stratified combustion, an experimental and computational fluid dynamics (CFD) coupled approach was employed. The intake section of the helical intake port was divided into four independent intake zones with equal areas by clockwise division: the upper right zone A, upper left zone B, lower left zone C, and lower right zone D. Each zone was supplied with a tracer gas to study the influence of key structural elements of the helical port on gas stratification characteristics within the cylinder. The results indicate that zone D had the highest intake mass, accounting for 27.3% of the total intake, while zone B had the lowest intake mass at 22.4%. In the combustion chamber, intake from zones A and B formed an upper-rich, lower-lean distribution pattern, while intake from zone C formed an upper-lean, lower-rich distribution pattern. The stratification concentration gradient might be quantitatively described thanks to the application of “density ratio.” Lift increased by 5.6% at a 15° intake port deflection angle because the combustion chamber’s maximum axial density ratio was 0.186 and its maximum swirl ratio was 3.57. Soot generation fell by 12.9% under axial stratification, although NOX generation increased by 4.9%.","PeriodicalId":509770,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2024-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1177/09544070241254424","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
In order to control gas stratification in diesel engine cylinders and achieve stratified combustion, an experimental and computational fluid dynamics (CFD) coupled approach was employed. The intake section of the helical intake port was divided into four independent intake zones with equal areas by clockwise division: the upper right zone A, upper left zone B, lower left zone C, and lower right zone D. Each zone was supplied with a tracer gas to study the influence of key structural elements of the helical port on gas stratification characteristics within the cylinder. The results indicate that zone D had the highest intake mass, accounting for 27.3% of the total intake, while zone B had the lowest intake mass at 22.4%. In the combustion chamber, intake from zones A and B formed an upper-rich, lower-lean distribution pattern, while intake from zone C formed an upper-lean, lower-rich distribution pattern. The stratification concentration gradient might be quantitatively described thanks to the application of “density ratio.” Lift increased by 5.6% at a 15° intake port deflection angle because the combustion chamber’s maximum axial density ratio was 0.186 and its maximum swirl ratio was 3.57. Soot generation fell by 12.9% under axial stratification, although NOX generation increased by 4.9%.
为了控制柴油发动机气缸内的气体分层并实现分层燃烧,采用了实验和计算流体动力学(CFD)耦合方法。将螺旋进气口的进气部分按顺时针方向划分为四个面积相等的独立进气区:右上区 A、左上区 B、左下区 C 和右下区 D。结果表明,D 区的进气量最大,占总进气量的 27.3%,而 B 区的进气量最小,占 22.4%。在燃烧室中,来自 A 区和 B 区的进气量形成了上富下贫的分布格局,而来自 C 区的进气量则形成了上贫下富的分布格局。由于采用了 "密度比",可以对分层浓度梯度进行定量描述。由于燃烧室的最大轴向密度比为 0.186,最大漩涡比为 3.57,因此在进气口偏转角为 15° 时,升力增加了 5.6%。在轴向分层条件下,烟尘生成量减少了 12.9%,但氮氧化物生成量增加了 4.9%。