In order to overcome the drawback (tuning reaction rate coefficients) of using a single mechanism in the chemical-kinetics-based turbulent premixed combustion modelling approach, a mechanism-dynamic-selection turbulent premixed combustion model has been developed, validated, and successfully applied to the combustion and emissions simulation of spark ignition gasoline engines. In this new model, based on the local thermal and turbulent conditions of any preheat cell, a certain chemical kinetic mechanism which can achieve the target ratio of turbulent flame speed to laminar flame speed is selected. To realise this goal, based on the laminar flame speed sensitivity analysis of an improved eTRF (ethanol toluene reference fuel) base chemical kinetic mechanism, a derived mechanism library has been generated. Based on enough experimental and DNS (direct numerical simulation) data of S_T/S_L, a mechanism selection database (mechanism as a function of Borghi-Peters coordinates) has been constructed and implemented into a CFD (computational fluid dynamics) code, also a classification scheme for identifying unburned, preheat, flame front, and burned zones of a combustion domain has been developed and implemented into the CFD code. The developed mechanism-dynamic-selection turbulent premixed combustion model has been validated using the combustion in a spherical constant volume and applied to the prediction of combustion and emissions of a spark ignition gasoline engine under transient cold start process. Validation results show that, without tuning any model parameters, the base mechanism, the derived mechanism library, the mechanism selection function, the classification scheme, as well as a simulation setup strategy for modelling engine transient cold start process, have good prediction performances and are practical for engine combustion and emissions simulation.

为了克服在基于化学动力学的湍流预混燃烧模型方法中使用单一机制的缺点（调整反应速率系数），已开发，验证并成功地将机理动态选择湍流预混燃烧模型应用于火花点火汽油发动机的燃烧和排放模拟。在这个新模型中，基于任何预热单元的局部热和湍流条件，选择可以实现湍流火焰速度与层流火焰速度的目标比率的某种化学动力学机制。为了实现此目标，基于对改进的eTRF（乙醇甲苯参考燃料）基础化学动力学机理的层流火焰速度敏感性分析，已生成派生的机理库。小号_Ť /小号_大号，已经建立了一个机制选择数据库（机制作为Borghi-Peters坐标的函数），并已实现为CFD（计算流体力学）代码，并且还提供了一种分类方案，用于识别燃烧的未燃烧区，预热区，火焰前沿区和燃烧区域已开发并实现为CFD代码。所开发的机构-动态选择湍流预混燃烧模型已通过使用球形恒定体积内的燃烧进行了验证，并已应用于瞬态冷启动过程中火花点火汽油发动机的燃烧和排放预测。验证结果表明，在不调整任何模型参数的情况下，基本机制，派生的机制库，机制选择函数，分类方案，