Abstract:

In the development process of an SUV model， in order to highlight the sense of sportive styling， a hollow roof spoiler is designed in the exterior styling. However， the application of the hollow roof spoiler results in a new aero-acoustics noise source， which seriously deteriorates the interior noise performance. Through the analysis of the wind tunnel test results and the numerical simulation， the mechanism of the noise caused by the hollow roof spoiler is identified in this paper. Firstly， the airflow accelerates in the hollow channel and directly hits the windshield， and secondly， the airflow is separated and coupled in the wake of the roof spoiler to form high turbulence intensity vortex radiation. Based on the noise generation principle， this paper proposes a corresponding optimization scheme： reducing the flux of the air flow passing through the channel； reducing the velocity of the air flow passing through the channel； changing the direction of the air flow passing through the channel. The corresponding optimization schemes are formed and verified by the wind tunnel test. The test results show that the optimization scheme has a significant effect on improving the articulation index in the vehicle and reducing the sound pressure level in the vehicle， with the sound pressure level reduced by 2 dBA at least， and the articulation index improved by 0.7%， 1.5%， 1.7% for each scheme. The research in this paper can provide an important basis for the hollow roof spoiler design and optimization.

Key words: aero-acoustic noise, wind tunnel test, acoustic sludge model, wind noise simulation, hollow roof spoiler