基于一维、三维及耦合模型的汽油机进气系统优化

Optimization of Gasoline Engine Intake System Based on 1D,3D and Coupled Simulations

建立了基于一维计算流体动力学(CFD)进排气系统的某4缸4行程电喷汽油机工作过程循环数值模型,在验证模型精度的基础上,对发动机的歧管长度和配气相位进行了优化。通过一维CFD模型计算得到的进气系统优化结果,建立了进气歧管的三维稳态CFD模型,分析了歧管各支管的流动阻力和流动均匀性。最后将一维与三维进气歧管模型耦合建立汽油机工作过程循环数值模型,对该发动机工作过程中进气歧管内的动态流动进行了详细解析,分析了歧管长度和配气相位对流动的影响。

In this paper, a working process numerical model of a 4-cylinder 4-stoke electronic fuel injection （EFI） gasoline engine based on 1D computational fluid dynamics （CFD） intake and exhaust system was established and testified, the intake manifold length and engine valve timing were optimized. Based on the optimized results using 1D model, a 3D steady CFD model of intake manifold was set up, and the pressure loss and the charge uniformity between sub-pipes were analyzed. Finally a 1D-3D coupled model for engine cycle simulation was set up, and the dynamic flow of intake manifold during the engine working process was analyzed in detail. Besides these, the effect of manifold length and valve timing on the intake flow was also analyzed.