Intake Noise Simulation Of Gasoline Engine Based On Co-simulation Of GT-Power?Fluent And LMS Virtual.Lab

Along with the improvement of people's living standards,the public enjoy higher requirements for the comfort of the vehicle.The noise level of the car has drawn more and more attention as it is an important factor affecting the comfort.Engine noise accounts for one of the main noise sources of the vehicle.Therefore,diminishing engine noise is one of the fundamental methods to decrease the automobile noise.Mechanical noise,aerodynamic noise and combustion noise are the main noise sources of the engine.As the sound source of the intake noise is very close to car compartments,it has a significant influence on vehicle interior noise.Thus,it is important to calculate and analyze the aerodynamic noise of the intake system.In order to be analyzed accurately,the aerodynamic noise in the intake system under the steady working condition of the engine was calculated using the co-simulation method in this paper,based on the three software,GT-Power,Fluent and LMS Virtual.Lab,which improves the efficiency of the analysis and the accuracy of the calculation.For simulating the actual running condition of the engine and providing more precise boundary condition for CFD calculation,an engine operating model was firstly established by GT-Power.In the process of the coupled simulation between GT-Power and Fluent,the velocity at the boundary of the intake system was used as the boundary condition for CFD calculation in Fluent,after the precision of the engine model was verified.The LES turbulence model with a prism layer of 0.01 mm thickness was applied in flow analysis.The pressure pulsation results calculated at each time step were preserved,which were finally imported into LMS Virtual.Lab as the acoustic excitation source of aerodynamic noise.Then,acoustic response was calculated with acoustic finite element method(AFEM).The accuracy of the co-simulation results was verified by the experimental results.Through the research of aerodynamic noise contour,the positions of the main sound sources for intake noise were determined.And according to analysis results,aerodynamic noise of intake system was reduced by adjusting the structure of intake manifold and pressure stabilizing cavity.The loudness,roughness and sharpness of sound quality objective parameters were also calculated in this paper,which also validated the accuracy of the co-simulation method.The changing trends of the loudness,roughness and sharpness of intake system with critical frequency bands were analyzed.Different models were compared to analyze influence of optimized structures on psychological parameters.