Analysis And Optimization Of Aerodynamic Noise Of Car Rearview Mirror

With the development of science and technology and economy, the level of humans’living become higher and higher. People enjoy the comfort of science and technology, and at the same time put forward the more stringent requirements on the environment. With the increase of car ownership and car speed increasing, the noise pollution is increasingly serious. Especially the rearview mirror, prominent in the body, bigger contribution to motor noise. This article obtains from the rear view mirror appearance, the rearview mirror surface pits of different shape and distribution of rearview mirror the influence of the aerodynamic noise, designed to reduce noise pollution, improve the driving comfort.In the simulation calculation, this paper is divided into three stages:The first stage, calculate the float flow out of the car. According to the actual situation, establish the three-dimensional model for vehicle, meshing and import import to FLUENT to calculate the steady float flow out of the car, and get the distribution of the noise of the body by broadband noise. The result shows that the rear-view mirror is the main noise source. Monitor the resistance of the aerodynamic of the car and compared with the official data to ensure the accuracy of this calculation.The second stage, calculate the aerodynamic noise. Firstly, setting nine monitor points, transient calculation the steady float flow using the LES simulation equation. Secondly, import the result to Virtual.Lab, analysis the acoustic response, by FFT changing, getting the Sound pressure series spectrum of all monitor points.The third stage, optimize the aerodynamic noise. Firstly, analysis the noise spectrum, ensure the plan of modify, secondly, set up the parameterized nonsmooth rearview mirror model, changing the parameter and monitoring the sound pressure spectrum. Comparing different plans to find the best one.This pit is verified through the calculation of noise of unsmooth surfaces help to reduce the aerodynamic noise of rearview mirror, reasonable pit shape, size and distribution can further reduce the aerodynamic noise of the rearview mirror.