Study On The Flow Field Simulation And Model Analysis Of Plastic Intake Manifold For A Three Cylinder Gasoline Engine

In recent years,with the influence of environmental problems and national policy,small-displacement turbocharged gasoline engines have become the mainstream of research for almost all automobile manufacturers.Engine intake system has an important effort on the power and economy of the engine.Intake manifold is one of the most important components in the intake system,and the plastic intake manifold with complex structure and excellent performance has been widely used.In this paper,based on the background of the small-displacement three-cylinder turbocharged engine project,the structural design and improvement of the plastic intake manifold are carried out.First of all,the mathematical model of the target engine working process is established,the flow characteristics and energy loss of the intake manifold are analyzed,and a complete model of three cylinder turbocharged gasoline engine is built with a one-dimensional simulation software Boost according to the data which includes engine structure parameters,valve lift curve,combustion parameters and other parameters.Under the premise to meet the performance requirements of the engine,the main structure size of the intake manifold is determined initially.Secondly,the intake manifold model is established using three-dimensional modeling software Creo2.0,the flow field analysis of the plastic intake manifold is carried out at 5500r/min steady state,and the rounded corners of the interior are rounded to avoid the sudden expansion or shrinkage of the flow cross section.As a result,the speed separation phenomenon is eliminated,the flow performance and the intake uniformity are improved,and the pressure loss is obviously reduced.Finally,each mode below 1000 Hz is intercepted after the modal analysis has been carried out using analysis software Abaqus,and the structure of the plastic intake manifold is modified according to the analysis results.After that,the first order mode of the improved plastic intake manifold is far away from the engine resonance frequency band,the possibility of resonance between the intake manifold and the engine is eliminated,and the intake manifold with better performance is obtained.which provides a technical reference for the subsequent design optimization of the project and has certain practical application value.