Performance Evaluation Of An Engine Intake Manifold System Based On CAE/CFD Analysis

As one of the key components of the engine intake system,the intake manifold has a direct impact on the fuel economy,emission characteristics and power performance of the whole engine,the engine intake manifold system comprises a throttle valve body,an intake flange,an inlet and outlet bends.At present,the problem of optimization analysis of intake manifold is a topic of great concern to engineers and scholars all over the world,and has important significance in research.Based on the research and development project of the intake manifold of a company,the finite element analysis method is used to modal analysis,burst pressure analysis and CFD analysis for engine intake manifold,and the corresponding tests to verify the simulation of the reliability.Firstly,ABAQUS software was used to generate the high quality volume grids,and the modal analysis and burst pressure simulation were carried out respectively,to determine the weak point when the engine produces resonance,on the basis of structural optimization,modal,blasting and CFD reanalysis are carried out.The fluid velocity distribution and the total inlet pressure distribution of the boundary layer were obtained by viscoelastic model Realizable k-epsilon using the coupling of AVLFIRE and fluid FLUENT software,the results show that the maximum uniformity of the fluid in the boundary layer is less than 5%,the total inlet pressure loss is in the range of 2.5Kpa,the results of modal analysis and blasting pressure analysis show that the first-order vibration frequency of the intake manifold increases obviously,avoiding the resonance frequency,and the deformation displacement of the intake manifold is reduced.At the same time,the blasting stress value is less than Fixed 9bar,intake manifold surface deformation area decreases,the overall satisfy the design requirements.In this paper,through the intake manifold numerical simulation and bench test,blasting pressure test combined to derive the engine characteristic curve data and intake manifold burst strength,compared with the experimental results,there is a certain error between the test and calculation,the error rate between the two is within 5%,which accords with the design requirements and verifies the accuracy ofthe numerical simulation,finally improves the engine intake manifold system performance,It provides the direction and basis for the research and development design and optimization of the intake manifold,effectively shortening the product development cycle and production cost.