摘要
直喷式汽油机的混合气形成质量依赖于缸内复杂湍流场.对缸内湍流场特性的全面认识和合理的控制有利于实现发动机的高效清洁燃烧.首先采用大涡模拟数值计算和粒子图像测速相结合的方式对缸内流场展开研究,获取了缸内瞬态涡量场信息,发现缸内大尺度涡团主要由进气射流和缸内原有流场的相互剪切作用产生,同时在不同周期之间,涡量场存在着明显的循环变动.然后应用本征正交分解方法对所获得的流场数据库进行深加工,更加科学和全面研究了缸内流场单一周期内的演变和多周期间的循环变动.同时还可以证明本征正交分解方法可以用来作为验证发动机缸内湍流场数值模拟结果准确性的有效工具.
In the direct inject engines,the fuel-air mixture quality largely depends on the complex in-cylinder air flow.Thus,understanding and appropriate control strategy for the in-cylinder turbulent flow field are important for clean and high-efficiency combustion process in the spark-ignition direct-injection engines.Large eddy simulation and particle image velocimetry were used to study the in-cylinder vorticity field.Results show that,large scale vortices are mainly generated by the shear force between inlet jet and In-cylinder flow field,and the cycle-to-cycle variations of vorticity field are obvious.The vorticity field database was analyzed using the proper orthogonal decomposition method to understand the transient and cycle-to-cycle variations characteristics.In addition,this study proves that proper orthogonal decomposition is an efficient tool to verify the simulation result to the measurement.
出处
《内燃机学报》
EI
CAS
CSCD
北大核心
2016年第3期246-252,共7页
Transactions of Csice
基金
国家自然科学基金资助项目(51376119
51506118)
关键词
汽油机
大涡模拟
粒子图像测速
本征正交分解
涡量场
循环变动
gasoline engine
large eddy simulation
particle image velocimetry
proper orthogonal decomposition
vorticity field
cycle-to-cycle variations
