预混点燃式天然气发动机燃烧过程CFD研究(一)

The CFD Simulation of Combustion Process in Premixed Ignition CNG Engine(1)

采用AVL三维CFD软件FIRE对一台预混点燃式天然气发动机的燃烧过程进行了CFD研究。通过模拟仿真得到了发动机缸内气体的压力场、流场、温度场及湍动能等信息,并详细分析了压缩及燃烧过程气体的流动、温度的分布以及湍动能对火焰传播的影响。在此基础上对点火提前角、燃空当量比对燃烧过程的影响进行了模拟研究,为该天然气发动机燃烧过程的设计优化提供了理论性指导。

The 3D CFD software AVL FIRE is used to simulate the combustion process of a premixed spark-ignition CNG engine. With the CFD simulation, some important information in the cylinder which could not easily be acquired in experiment was obtained, such as the pressure, velocity, temperature fields, the TKE（turbulence kinetic energy） and so on. Furthermore, the effect of the characteristic of the flow field, the temperature distribution and the TKE（turbulence kinetic energy） of the compression and burning process on the flame propagation was analyzed in detail. On this basis, the effects of ignition angle and the fuel equivalence ratio to the process of combustion are simulated. The investigation about the information from numerical simulation gives some theory guidance for designing and optimizing combustion performance of this CNG engine.