【摘要】 以甲醇发动机为研究对象,建立了三维数值计算模型,并对模型的有效性进行了验证,在此基础上,对直口、敞口和缩口3种不同形状燃烧室的工作过程进行计算,详细分析了燃烧室形状对缸内速度场分布及湍动能分布,火焰传播过程,燃烧压力、压力升高率、缸内温度及NO排放的影响.结果表明,直口燃烧室的燃烧持续期居中,并有适合的压力升高率,NO排放也相对较低,故综合考虑发动机性能和生产工艺性,选择直口燃烧室.更多还原

【Abstract】 The three-dimensional mathematical model of combustion process based on a methanol engine was established,and the accuracy of the model was validated.On this basis,the influence of three types of combustion chamber shape(straight port,reduced port and exposure port)on combustion process was studied.The gas flow and turbulent kinetic energy field,combustion pressure,the rate of pressure rise,temperature and NO emissions in the cylinder were treated in detail.The results show that there is proper combustion duration,proper rate of pressure increase and lower NO emission in the straight port.In this case,the straight port combustion chamber is the right choice in terms of engine performance and production techniques.更多还原