The current study aims at simulating the in-cylinder combustion process in a diesel engine and investigating the engine performance and pollutant formation. The combustion simulation is performed on a 3D sector employing appropriate models for various physical and chemical processes contributing in the combustion phenomenon. The overall model includes Transition SST turbulence model, eddy dissipation model for turbulence chemistry interaction, Moss–Brookes model for soot calculation and Zeldovich mechanism for NO production other than the usual transport equations. The numerical solutions are based on the finite volume discretization of the governing partial differential equations. Engine performance has been studied in terms of pressure, temperature and heat release rate while the pollutants formation has been investigated in terms of soot and thermal NO production. The results show that the ignition delay is quite short and that the injection timing may be successfully employed to control the combustion behavior. The simulation results are quite consistent with the expected behavior of the target variables indicating that the CFD analysis can be successfully employed in the diesel engine design. The results validation may be acknowledged in view of the mesh independence test, literature comparison and justification of the models.

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柴油机污染物形成的数值模拟研究

目前的研究旨在模拟柴油发动机的缸内燃烧过程，并研究发动机性能和污染物的形成。燃烧模拟是在 3D 扇区上执行的，使用适当的模型来处理导致燃烧现象的各种物理和化学过程。整体模型包括 Transition SST 湍流模型、湍流化学相互作用的涡耗散模型、烟尘计算的 Moss-Brookes 模型和除通常的传输方程之外的 NO 产生的 Zeldovich 机制。数值解基于控制偏微分方程的有限体积离散化。已根据压力研究发动机性能，温度和热释放率，而污染物的形成已经在烟尘和热 NO 产生方面进行了研究。结果表明点火延迟非常短，并且可以成功地采用喷射正时来控制燃烧行为。仿真结果与目标变量的预期行为非常一致，表明 CFD 分析可以成功地用于柴油机设计。考虑到网格独立性测试、文献比较和模型的论证，可以确认结果验证。仿真结果与目标变量的预期行为非常一致，表明 CFD 分析可以成功地用于柴油机设计。考虑到网格独立性测试、文献比较和模型的合理性，可以确认结果验证。仿真结果与目标变量的预期行为非常一致，表明 CFD 分析可以成功地用于柴油机设计。考虑到网格独立性测试、文献比较和模型的论证，可以确认结果验证。