Flow Field Analysis And Structure Optimization Of Automobile Air Filter

The air filter provides sufficient and clean air for the engine.Its performance not only affects the reliability and service life of the engine,but also affects its power,economy and emissions to a great extent.How to improve the flow characteristics of the filter and reduce the flow resistance is the key to improve the filtration efficiency,prolong the life of the filter,improve the engine power and fuel economy.However,because the internal structure of the air filter and the working condition of the air filter are complex and changeable,it is very difficult to obtain the real flow characteristics in the filter only through the experiment or experience,and the cost is high,the time is long,and the whole surface data of the internal flow of air flow can not be obtained.With the extensive application of computer technology in the field of industrial research and development design,it is now the most widely used means to analyze the variable internal flow characteristics by using computational analysis software.When the filter structure is optimized,the computational fluid dynamics CFD(Computational Fluid Dynamics)analysis software is used to carry out the simulation analysis.The analysis efficiency is greatly improved,and the analysis results are more accurate and comprehensive.In view of the large flow resistance of a diesel pickup truck air filter,a structural optimization design is proposed.First,the UG modeling software is used to establish the solid model of the air filter,then the necessary simplification and geometric cleaning are carried out to divide the grid,and then the boundary constraints are set reasonably.In the ANSYS Fluent simulation software,the SIMPLE algorithm and the standard k-e turbulence model are used to simulate the internal flow field of the filter housing.The graphic results of velocity and pressure of airflow inside the filter are obtained,and the flow field characteristics of the filter are analyzed.Finally,according to the results of simulation analysis,the area of the inlet and outlet of the filter,the position of the inlet and outlet and the processing of the import and export round angle are optimized,and the simulation of the model after the optimization is simulated again.In addition,the air filter after the structure optimization was tested,and the two samples were entrusted to the national motor vehicle quality supervision and Inspection Center(Chongqing)for inspection.The results of the optimized simulation analysis and the test report of the trial samples show that the flow field uniformity of the optimized filter has been obviously improved and the pressure difference between the inlet and outlet is obviously reduced,and it is also proved that the optimization scheme is reasonable and feasible.