摘要
利用CONVERGE软件建立了半直喷式液压自由活塞发动机的三维计算流体力学(computational fluid dynamics,CFD)仿真模型,研究了喷射角度、喷油定时、缸头倾角、进气压力对燃料捕集和混合气生成的影响。结果表明:随喷射时刻的推迟,燃料捕获率增加,蒸发时间变长;喷射角度越大,燃料捕获率越高,蒸发时间随喷射角度增加先减小后增大,合理的喷射角度和喷油定时下,燃料捕获率能达到99%以上;缸头倾角对燃料捕获影响不大,较大的缸头倾角下,燃料蒸发速度更快,缸内燃料分布更为均匀;随进气压力的提高,燃料捕获率下降,蒸发时间减少,与改变喷油参数相比,在相同的燃料捕获率下,改变进气压力得到的混合气更加均匀,混合气不均匀度最低达到0.5。
A three-dimensional computational fluid dynamics(CFD)simulation model of a two-stroke semi-direct injection hydraulic free-piston engine(HFPE)was built by the CONVERGE.The effects of the injection angle,fuel injection timing,chamfer of cylinder head,intake pressure on fuel capture and mixture formation were studied.The results show that as the injection timing is delayed,the fuel capture rate and evaporation time increase.The fuel capture rate increases with the increase of injection angle,while the evaporation time decreases first and then increases as the injection angle increases.With the appropriate injection angle and injection timing,the fuel capture rate can reach 99%or more.The larger the cylinder head chamfer,the faster the fuel evaporates and the more uniformly the fuel distributes in the cylinder.As the intake pressure increases,the fuel capture rate and the evaporation time decrease.Under the same fuel capture rate,more uniform mixture can be obtained by changing the intake pressure than by changing the fuel injection parameters.The minimum unevenness of the mixture can reach 0.5.
作者
董翔宇
汪洋
徐帅卿
朱瑞
胥奇
甄旭东
DONG Xiangyu;WANG Yang;XU Shuaiqing;ZHU Rui;XU Qi;ZHEN Xudong(State Key Laboratory of Engines,Tianjin University,Tianjin 300072,China;School of Auto-Mobile and Transportation,Tianjin University of Technology and Education,Tianjin 300222,China)
出处
《内燃机工程》
EI
CAS
CSCD
北大核心
2021年第3期8-15,共8页
Chinese Internal Combustion Engine Engineering
基金
国家自然科学基金项目(51476113,51776135,51406135)。
