氢燃料发动机三维数值模拟研究

通过CFD软件STAR-CD建立了缸外预混合氢燃料发动机三维模拟仿真模型。对比氢燃料发动机与汽油发动机的性能发现,氢燃料发动机具有易点燃、火焰传播速度快、峰值压力及峰值温度高等特点。但氢气密度低,与空气形成的混合气单位体积的热值低,导致采用缸外预混合方式的氢燃料发动机比汽油机功率低15%左右。研究了过量空气系数和点火提前角对氢燃料发动机性能及NOx排放的影响,为提高氢燃料发动机的动力性能和排放性能提供依据。

Research on 3-D Numerical Simulation of Hydrogen Engine

The three-dimensional simulation model was built by the CFD software called STAR-CD for the hydrogen engine that was premixed outside cylinder.Compared with gasoline engine,the hydrogen engine had the characteristic of being easily ignited,fast spreading flame,higher peak pressure and higher peak temperature.However,the output power of hydrogen engine was about 15 percent lower than that of gasoline engine due to the low heat value per unit volume of hydrogen-air mixture caused by the low density of hydrogen.The influences of excess air ratio and ignition advance angle on engine performance and NOx emission were discussed for further,which was helpful to improve the dynamic and emission performance of hydrogen engine.