基于三维粒子图像测速技术的滚流运动研究  

Measurement of Tumble Flow Based on 3D Stereo-PIV

作　　者：李卫 刘大明[2] 田福全[3] 鲁祯 王天友[3] 王玉春[4] Li Wei;Liu Daming;Tian Fuquan;Lu Zhen;Wang Tianyou;Wang Yuchun(Engine R&D Center,Weichai Power Company Limited,Weifang 261061,China;School of Automotive and Transportation,Tianjin University of Technology and Education,Tianjin 300222,China;State Key Laboratory of Engines,Tianjin University,Tianjin 300072,China;Department of Mechanics,Tianjin University,Tianjin 300072,China)

机构地区：[1]潍柴动力股份有限公司发动机研究院,山东潍坊261061 [2]天津职业技术师范大学汽车与交通学院,天津300222 [3]天津大学内燃机燃烧学国家重点实验室,天津300072 [4]天津大学力学系,天津300072

出　　处：《内燃机学报》2021年第3期225-232,共8页Transactions of Csice

基　　金：国家杰出青年科学基金资助项目(51525603);国家自然科学基金资助项目(51706155);天津市教委科研计划资助项目(2017KJ114);天津职业技术师范大学人才启动资助项目(KYQD14050).

摘　　要：借助自主搭建的三维粒子图像测速系统对4气门汽油机缸盖进行了稳流条件下缸内流场测量,得到缸内不同测量截面处流场的三维速度分布,对不同气门升程下缸内流场结构进行了分析,并基于离面速度分布对滚流比进行了计算.研究发现:缸内滚流流场在垂直于气缸轴线的测量平面内主要体现为位于进/排气门侧的进气射流;较高的气道压差可以保证流场结构充分发展,使流场结构趋于稳定,滚流比计算结果准确性提高;测量截面处流场离面速度分布直接影响滚流比计算结果,过小的可视区域无法将典型的流场结构(如靠近壁面的射流结构和局部涡团结构)包括在测量范围内,导致滚流比计算结果产生偏差.测量截面的位置直接影响流场离面速度的测量结果,测量截面太靠近缸盖底平面,缸内流动得不到充分发展,反之典型流场结构因衰减而不再明显,最终影响滚流比的计算结果.In-cylinder flow field in a four-valve gasoline engine was measured under steady flow test condition by the self-built 3D Stereo-PIV(particle image velocimetry)system.Three-dimensional velocity distribution of the flow field in different measuring sections of the cylinder was obtained,and then the distribution of flow field structures in the cylinder and the calculated tumble ratio under different valve lifts were analyzed.It is found that the tumble flow field is mainly embodied as two intake jets on the intake and the exhaust valve sides in the measuring plane,which is perpendicular to the cylinder axis,respectively.Higher intake port pressure drop can ensure the full development of the flow field structure and make the flow field structure to be stable,helping to improve the accuracy of the tumble flow ratio calculation result.The off-plane velocity distribution in the measuring section directly affects the calculation results of the tumble ratio.An excessively small viewing area would lead to the typical flow field structure,such as jet structures near the cylinder wall and local vortex structures,unavailable in measurement range,and hence make the tumble ratio to deviate from the real value.The location of measuring sections has a vital effect on the off-plane velocity distribution.If the measuring section is too close to the bottom side of the cylinder head,the flow in the cylinder is not fully developed.On the contrary,the typical flow field structure is no longer obvious because of the energy decay of intake jets.The change in these factors ultimately affects the calculation of the tumble ratio.

关 键 词：汽油机 三维粒子图像测速 滚流比 稳流试验 

分 类 号：TK411[动力工程及工程热物理—动力机械及工程]