进气管对柴油机进气不均匀性影响的一三维耦合仿真

Impact of Intake Pipe's Structure on the Non-Uniformity of Intake Air for Diesel Engine with one-and Three-Dimensional Coupled Simulation Model

利用AVL BOOST和AVL FIRE分别建立了某Ⅴ型八缸柴油机的一维热力学仿真计算模型和发动机进气管的三维流动仿真模型,通过一三维耦合仿真计算分析了Ⅱ型进气管和环型进气管的进气不均匀性和进气管内部的瞬时三维流场分布情况。研究结果表明:同侧进气管内连续发火的两个气缸存在不同程度的"抢气"现象;与Ⅱ型进气管相比,环型进气管结构能增大进气腔容积,有效地减弱同侧进气支管内相邻发火两气缸之间的"抢气"效应,进而降低发动机的进气不均匀度。

AVL BOOST and AVL FIRE were employed to establish a one dimensional thermal dynamic simulation model and a three dimensional fluid simulation model of intake pipe for a V-type 8-cylinder diesel engine respectively. The coupled simulation of one-dimensional model and three-dimensional model was adopted to analyze the non-uniformity of intake air between a Ⅱ-type intake pipe and a ring intake pipe as well as the transient flow field inside the manifolds with different crank angle. It is showed that there is an air snatch effect between the two cylinders in fire order on the same side; compared with the Ⅱ-type intake