韦虹,马瑞博,姬费帆,等.直喷氢气发动机分层稀薄燃烧的大涡模拟研究[J].内燃机工程,2025,46(2):1-10.
直喷氢气发动机分层稀薄燃烧的大涡模拟研究
Large Eddy Simulation of Stratified Lean Combustion in a Direct Injection Hydrogen Engine
DOI：10.13949/j.cnki.nrjgc.2025.02.001
关键词:氢气射流  简化喷射器模型  分层稀燃  直喷氢气发动机  大涡模拟
Key Words:hydrogen jet  simplified injector model  stratified lean combustion  direct injection hydrogen engine  large eddy simulation（LES）
基金项目:
作者单位E-mail
韦虹 宁波吉利罗佑发动机零部件有限公司，宁波315336 weihong@geely.com 
马瑞博 宁波吉利罗佑发动机零部件有限公司，宁波315336 maruibo@geely.com 
姬费帆 同济大学 汽车学院，上海 201804 2133482@tongji.edu.cn 
孟硕 同济大学 汽车学院，上海 201804 95mengshuo@tongji.edu.cn 
马文中 宁波吉利罗佑发动机零部件有限公司，宁波315336 wenzhong.ma1@geely.com 
马俊杰 宁波吉利罗佑发动机零部件有限公司，宁波315336 junjie.ma1@geely.com 
韩志玉* 同济大学 汽车学院，上海 201804 hanzhiyu@tongji.edu.cn 
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摘要:为探究直喷氢气发动机分层稀薄混合气的形成过程及其对燃烧过程的影响，基于大涡模拟（large eddy simulation， LES）方法对两款不同尺寸的氢气喷射器在相同发动机工况下的氢气射流、混合过程和燃烧过程进行了三维计算流体力学（computational fluid dynamics， CFD）数值模拟研究。为了降低计算时间并保持较高计算精度，采用了一种喷射器简化方案。喷射器简化方案的有效性分别通过定容弹和发动机模拟进行了验证。在定容弹模拟中，两款氢气喷射器在不同定容弹背压下的射流贯穿距与试验数据的均方根误差均在5.0%以内。在发动机模拟中，分别装有两款氢气喷射器的发动机在燃烧阶段的缸压与试验数据基本相符。发动机模拟结果表明：两款喷射器的发动机混合气形成过程在基本特征上没有实质性区别，但小流量喷射器发动机在点火前的混合气分层效果较好，且燃烧循环变动更小。喷射结束时刻（end of injection， EOI）显著影响氢气分层稀薄燃烧稳定性，过度推迟EOI会造成火花塞附近混合气过稀，从而导致起燃缓慢甚至失火。
Abstract:To investigate the formation process of the stratified lean mixture in a direct injection hydrogen engine and its influence on the combustion process， three-dimensional computational fluid dynamics （CFD） numerical simulation was carried out on the hydrogen jet， mixing process， and combustion process of two hydrogen injectors of different sizes under the same engine operating conditions based on large eddy simulation （LES） method. An injector simplification scheme was adopted to reduce the calculation time and maintain high accuracy. The effectiveness of the injector simplification scheme was verified by constant-volume vessel and engine simulations respectively. In the constant-volume vessel simulation， the root mean square errors of the jet penetrations of the two hydrogen injectors under different vessel back pressures compared to the test data were within 5.0%. In the engine simulation， engine cylinder pressures in the combustion stage with the two hydrogen injectors were basically consistent with the test data. The engine simulation results show that there is no substantial difference in the basic characteristics of the engine mixture formation process of the two injectors， but the engine with the small-flow injector has a better mixture stratification effect before ignition and smaller combustion cycle variation. The end of injection （EOI） significantly affects the stability of hydrogen-stratified lean combustion. Excessive delay of EOI will cause the mixture around the spark plug to be too lean， resulting in slow ignition or even misfire.
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