Study On Aerodynamic Noise Control Of Vehicle Intercooler Outlet Pipe

Although the use of turbochargers improves the fuel efficiency of the engine and reduces carbon emissions,it is accompanied by more complex airflow in the intake system,which exacerbates the noise problem of the car.In this paper,the source of aerodynamic noise in the pipeline is analyzed for the problem of aerodynamic noise in the outlet pipe of an automobile intercooler,and the influence of the change of the pipeline structure on the aerodynamic noise is studied.First,a model of the fluid domain of the intercooler outlet pipe is established.Then,according to the characteristics of the flow field inside the pipeline,it is determined that the aerodynamic noise in the pipeline is dominated by dipoles,and the co-simulation method is used for numerical simulation.The flow field uses the SST k-ω+LES models,and the sound field use the finite element method.Finally,the reliability of the simulation method is verified by comparing with the experimental results,and the structure is optimized.According to the numerical simulation of the aerodynamic noise in the outlet pipe of the intercooler,it is found that the aerodynamic noise in the pipe is mainly generated at the elbow,so a model is established with the elbow as the research object.The direction of the elbow,the radius of curvature of the corner,the diameter and the different inlet and outlet lengths are studied,and the influence of the different temperatures of the medium in the air outlet pipe of the intercooler on the aerodynamic noise is also studied.The results show that the aerodynamic noise in the pipeline gradually decreases with the increase of the bending angle,and the influence of the non-acute angle bending on the aerodynamic noise first increases and then decreases with the change of the direction;As the radius of curvature of the elbow increases,the sound pressure level inside the elbow decreases gradually;With the increase of the diameter of the elbow,the sound pressure level in the pipeline also increases,and the influence of the aerodynamic noise is also small when the diameter change rate is small;For short elbows,the aerodynamic noise in the pipe will be reduced regardless of whether the inlet or outlet is increased by a certain length;With the increase of the air temperature in the pipe,the sound pressure level in the pipe gradually decreases,but the change of the air temperature in the pipe has little effect on the aerodynamic noise in the pipe.Through the analysis results of the aerodynamic noise of the elbow,the structure of the air outlet pipe of the intercooler was optimized,and the aerodynamic noise in the air outlet pipe of the intercooler was significantly improved.This study provides a reference for the optimization of the turbocharger intake system pipeline and other pipelines with aerodynamic noise problems.