内燃机压缩过程冷态流场的大涡模拟

Large-Eddy Simulation of Turbulent Flow in the Compression Process of Internal Combustion Engine

通过修改发动机多维CFD计算程序KIVA-3V,建立了内燃机压缩过程冷态流场的大涡模拟(LES)计算模型。利用此模型对内燃机压缩过程中缸内流场的水平速度及湍流动能进行了详细分析,并与k-ε模型进行了比较。结果表明与采用k-ε模型计算时相比,采用LES计算时显示了更为复杂的湍流结构,而且LES所能捕捉到的涡团结构范围要大于k-ε模型。同时,采用LES计算时得到的湍流动能要远远低于k-ε模型。

By amending the engine CFD package （KIVA -3V）, the large-eddy simulation （LES） model of turbulent flow in the process of compression of internal combustion engine was built. The horizontal speed and turbulent kinetic energy of turbulent flow in the compression process were simulated by this model. The results show that comparing with k - ε model, LES model shows significantly different and relatively more complex turbulent structures. Furthermore, the range of vortical structures that LES model can capture is wider than k - ε model. At the same time, turbulent kinetic energy of k -ε model is much higher than that of LES.