脉冲转换排气系统三维非定常流动计算研究

对大功率8缸柴油机采用的脉冲转换排气系统进行了三维非定常流动计算,针对发动机实际排气管形状,计算物理模型采用多面体网格单元,排气管进口边界条件采用简化的用于一维性能计算的质量流量条件,湍流模型采用标准kε-模型。结合对排气管开启、关闭时刻点以及排气最大流量点的分析,探讨了脉冲转换排气系统的流动机理。

Research on Calculation of 3D Unsteady Flow for Pulse Converter Exhaust System

A three-dimensional unsteady flow for the pulse converter exhaust system of 8 cylinder diesel engine was numerically simulated. For the actual exhaust manifold shape, the polyhedral mesh cells were used for calculating the physical model, the 1D simplified mass flow conditions for performance calculation were used as the boundary conditions of exhaust manifold, and the standard model was used as the turbulent model. The flow mechanism of pulse converter exhaust system was discussed by analyzing opening points, closing points and max mass flow points of exhaust manifold.