CH4喷射参数对缸内分层及燃烧过程的模拟研究

Study on Effect of CH4 Injection Parameters on In-cylinder Stratification and Combustion Process

利用BOOST软件构建一维仿真模型得到边界的温度与压力,将其作为CFD软件的初始和边界条件,在螺旋气道各区的角平分线中心设置喷嘴,研究CH4分层的影响因素及分层特性。计算结果表明:螺旋气道左上区中心喷射CH4能形成环形分布;喷射位置对缸内分层的影响最大,喷射压力最小;与均质混合相比,CH4环形分布的Soot、CO、HC实现超低排放,但NOx较高。

One-dimensional simulation model was established using AVL BOOST,then the pressure and temperature curve were obtained and used as the CFD initial and boundary conditions.CH4 injectors were set up in center of angular bisector in each area of cross-section in helical port and factors in CH4 stratification and stratified combustion characteristic were investigated.Results show that the gas injected from upper left will form a ring around the center of the cylinder stratification.The injection position has the greatest effect on the in-cylinder stratification,while the injection pressure has the smallest.Also,Soot,CO and HC of CH4 annular stratification are ultra-low emissions,NOxis higher,respectively,of the counterparts of uniform intake mixing.