【作者】 包广元； 张韦； 陈朝辉； 蒋倩昱；

【Author】 Bao Guangyuan;Zhang Wei;Chen Zhaohui;Jiang Qianyu;Yunnan Key Laboratory of Internal Combustion Engine,Kunming University of Science and Technology;

【机构】 昆明理工大学云南省内燃机重点实验室；

【摘要】 搭建基于油流法的可视化气道稳流实验台,以YN33单螺旋进气道的共轨柴油机为研究对象,进行可视化稳流测试;同时构建包括气道-气门-气缸的CFD仿真模型,开展稳态-瞬态流场数值模拟,利用试验与模拟相互验证,将两种手段相结合,分析缸内流场演化历程。结果显示:气缸内壁面的油流痕迹分布与速度矢量分布呈现较好的对应关系;通过缸内瞬态流场分析可知,气缸及燃烧室内各径向截面的流场强度,在进气行程主要由进气流动主导,而在压缩行程则主要由活塞运动所主导;挤入ω燃烧室的气体涡流会因旋转半径的减小而加强,在燃烧室底部气体的涡流则受壁面摩擦影响而减弱,压缩过程中活塞运行至上止点附近,此时大部分滚流均被压碎,无论是缸内和燃烧室内滚流比都小于0.25。更多还原

【Abstract】 A visualized airway steady flow test bench based on oil flow method was built.The common rail diesel engine of YN33 single spiral inlet was used as the research object to carry out visual steady flow test.At the same time,the CFD simulation model including airway-valve-cylinder was constructed.The steady-state transient flow field numerical simulation uses the mutual verification of experiments and simulations to combine the two methods to analyze the evolution history of the flow field in the cylinder.The results show that the oil flow trace distribution on the inner wall surface of the cylinder has a good correspondence with the velocity vector distribution.The transient flow field analysis in the cylinder shows that the flow field strength of each radial section in the cylinder and the combustion chamber is mainly in the intake stroke.It is dominated by the intake air flow,and the compression stroke is mainly dominated by the piston movement;the gas eddy current squeezed into the ω combustion chamber is strengthened by the decrease of the rotation radius,and the vortex of the gas at the bottom of the combustion chamber is weakened by the wall friction.During the compression process,the piston runs to the vicinity of the top dead center.At this time,most of the rolling flow is crushed,and both the in-cylinder and the combustion chamber have a tumble ratio of less than 0.25.更多还原