缸内直喷氢内燃机控制参数对混合气形成及燃烧特性的影响研究OA北大核心

Based on an in-line 4-cylinder 4-stroke direct injection hydrogen internal combustion engine,a three-dimensional(3D)computational fluid dynamics(CFD)simulation model was established.The effects of engine control parameters on mixture formation and combustion characteristics were investigated.The results show that the peak values of in-cylinder pressure and heat release rate increase,and the combustion phases delay with the increase of equivalence ratio.The decreased equivalence ratio results in a similar but leaner mixture distribution in the cylinder.The mixture distribution that the rich mixture closer to the spark plug is the key to accelerating the flame propagation.With the delay of hydrogen injection timing,the peak values of in-cylinder pressure and heat release rate increase,the ignition delay period is shortened,and the combustion phase is advanced.The mixture distribution in the cylinder is a decisive factor in the effects of injection pressures and injection timings on the combustion process.