单总管排气系统多维非定常湍流数值模拟

Numerical Simulation on Multi Dimensional Unsteady Turbulent Flows in the Single Plenum Exhaust System

采用任意拉格朗日－欧拉法，对柴油机三缸排气管进行二维非定常湍流数值模拟．湍流模型采用亚网格尺度模型，入口边界的流动随排气相位变化．模拟结果显示：当排气管处于一个缸排气时，流动出现很强的旋涡、回流及高压区；而当两个缸同时排气时，旋涡区消失，回流和高压区有较大的削弱．

The arbitrary Lagrange Euler (ALE) method is applied to simulate the 2 D unsteady turbulent flows in the single plenum exhaust system. The effects of turbulence are represented by a generalized SGS turbulent model. The inflows change with the exhaust phase. Simulation results show that strong eddy current, recirculation and high pressure region will be produced when only one branch pipe is exhausting, and that they will be weakened when two pipes are simultaneously exhausting.