CAE-Based Prediction of Aero-Vibro-Acoustic Interior Noise Transmission for a Simple Test Vehicle 2014-01-0592
The interior noise in a vehicle that is due to flow over the exterior of the vehicle is often referred to as ‘windnoise’. In order to predict interior windnoise it is necessary to characterize the fluctuating surface pressures on the exterior of the vehicle along with vibro-acoustic transmission to the vehicle interior. For example, for greenhouse sources, flow over the A-pillar and side-view mirror typically induces both turbulence and local aeroacoustic sources which then excite the glass, and window seals. These components then transmit noise and vibration to the vehicle interior.
Previous studies by the authors have demonstrated validated CFD (Computational Fluid Dynamics) techniques which give insight into the flow-noise source mechanisms. The studies also made use of post-processing based on temporal and spatial Fourier analysis in order to quantify the amount of energy in the flow at convective and acoustic wavenumbers.
In the present study, the previously validated transient CFD techniques are used to describe sources that are input to frequency-based vibro-acoustic methods in order to predict interior noise. This combined aero-vibro-acoustic simulation approach is supported by an experimental programme initiated by Hyundai Motor Company (HMC) in which measurements of the internal noise were made on a simplified test structure at two speeds (110kph and 130kph), and two yaw conditions (0° and 10°), against which the predicted interior noise levels are compared.