基于1D和3D耦合的发动机进气歧管仿真研究

Study of Engine Intake Manifold Based on 1D-3D Coupling Simulation

进气系统在很大程度上影响了发动机的动力性、经济性和排放性。前期建立了一维仿真模型,比较真实的反映了发动机的性能,但还是未能真实的反映出管道的真实结构,像一些拐角、突变区域等。进气歧管的设计校验中,虽然三维稳态和瞬态计算能够模拟各个支管的压力分布情况,但是仅用三维计算不能实时得到一维的准确边界,且计算时间太长,不能从整个发动机上模拟瞬态进气过程和谐振效应带来的进气不均匀性。因此,要在1D模型中获得更准确的瞬态边界条件来计算进气歧管的三维流动,或更进一步研究进气歧管结构形状对发动机性能的影响,来指导优化进气歧管的设计。文章以发动机1D燃烧开发软件为基础与3D流体软件相耦合来解决进气歧管设计中瞬态进气过程。

The intake system greatly affects the power, economy and emissions of the engine. One-dimensional simulation model was established in the early stage, which reflects the performance of the engine, but it still fails to reflect the true structure of the pipeline, such as some corners and abrupt areas. Although the three-dimensional steady-state and transient calculation can simulate the pressure distribution of each branch pipe in the design calibration of the intake manifold, it cannot get the accurate one-dimensional boundary in real time and fails to simulate the intake non-uniformity caused by transient intake process and resonance effect from the whole engine. At the same time, the long period of calculation in the 3 D simulation is also a big issue. Therefore, more accurate transient boundary conditions should be obtained in the 1 D model in order to calculate the three-dimensional flow of the intake manifold as well as the influence of intake manifold structure shape on engine performance for further optimization of intake main fold design. In this paper, the transient intake process in the intake manifold design are solved by coupling engine 1 D combustion development software with 3 D fluid software.