双火花塞位置对发动机性能影响仿真研究

Simulation Study on the Influence of Dual Spark Plug Position on Engine Performance

研究基于三维计算流体力学(CFD)仿真平台,搭建正丁醇双火花塞发动机单缸模型。采用正丁醇化学反应动力学机理,通过数值模拟的方法,设置3组不同的双火花塞布置方案,分析双火花塞布置对发动机燃烧和排放性能的影响。研究结果表明,双火花塞距离过长或过短均不能使发动机获得良好的动力性,A=0.50方案能获得最高的缸温和缸压峰值,且放热率最高,燃烧前期的累计放热量最多,此时的发动机动力性最好。较高的缸温导致A=0.50时NOX排放最高,但SOOT排放最低。综合HC和CO排放结果来看,A=0.25时的排放性能最差,A=0.50和A=0.75时的HC和CO排放效果相当。

Based on 3D computational fluid dynamics(CFD)simulation platform,a single cylinder model of n-butanol dual spark plug engine is established.Based on the kinetic mechanism of chemical reaction of n-butanol,three sets of different dual spark plug arrangement schemes are set up by numerical simulation to analyze the effects of dual spark plug arrangement on combustion and emission performance of engine.The research results show that neither too long nor too short distance between two spark plugs can make the engine obtain good power performance.A=0.50 scheme can obtain the highest peak value of cylinder temperature and cylinder pressure,and the highest heat release rate,the highest cumulative heat release in the early stage of combustion,and the best engine power performance at this time.Higher cylinder temperature results in the highest NOX emission and the lowest SOOT emission when A=0.50.Combined HC and CO emission results,A=0.25 have the worst emission performance,while A=0.50 and A=0.75 have comparable HC and CO emission effects.