Structural Performance Optimization Of An Intake Manifold Based On CAE/CFD Analysis

For the engine,the intake manifold is one of the most important components in its intake system.Its structure will have an important impact on the uniformity of engine intake and intake resistance,and then affect the fuel economy,power and emission of the whole engine.Therefore,the design,analysis,optimization and manufacturing of intake manifold has always been a topic of concern for engineers and scholars in the automotive field,which has a very important research significance.The traditional design of engine intake manifold mainly depends on constant flow experiment and staff experience,but this method is costly and time-consuming.With the development of computer technology,more and more computer-aided software is applied to automobile development.In this paper,the intake manifold is designed and developed based on computer-aided design technology.The intake manifold of the engine is analyzed by means of modal analysis,CFD analysis and burst pressure analysis of finite element analysis theory,and its structure is optimized.The sample is made by mold injection,and the accuracy of simulation analysis is verified by burst pressure test and airway pressure loss test.Firstly,the volume grid of the product is generated by ANSYS software,and the product is analyzed by CAE modal analysis and burst pressure analysis software to judge the weak position where the engine intake manifold is easy to crack and damage.Secondly,the structure is optimized for the weak position.After the optimization,the modal analysis and burst analysis are carried out again to obtain the analysis results that meet the design requirements.Reuse AVL＿Fire software carries out CFD analysis to obtain the distribution of overall airway fluid velocity and total intake pressure in the product boundary layer.Finally,it obtains that the airway intake pressure loss of the whole intake manifold is ≤ 1.8kpa,and the fluid heterogeneity in the airway is less than 8%.Through the comparison of burst pressure test,air pressure distribution and loss test and simulation analysis,the first-order vibration frequency of intake manifold modal analysis after structural optimization is significantly improved,avoiding the frequency of resonance.At the same time,the burst pressure value in the test is not less than 7bar higher than the requirement,the surface strength of intake manifold is increased,and the overall deformation area is reduced,which meets the design requirements.According to the combination of CAE and CFD analysis of engine intake manifold with burst pressure test,air flow pressure distribution and loss test,the data of burst strength and airway uniformity of intake manifold are obtained.Through the comparison between actual test and simulation analysis,there is an error between them,but the overall error rate is limited to less than 5%,which meets the design requirements and confirms the reliability of CAE and CFD analysis,Finally,by improving the structure of engine intake manifold and improving its dynamic performance,through the comparison of CAE and CFD aided design,structural optimization and actual test data,the data error of the two is controlled within 5%,which meets the design standards in the industry,provides theoretical basis and direction guidance for the design and optimization of engine intake manifold and other products in the future manufacturing industry,and effectively reduces the development and manufacturing cost and product development cycle.