Hybrid CFD/FEM-BEM simulation of cabin aerodynamic noise for vehicles traveling at high speed

Abstract

Flow passing a vehicle may lead to the increase of the cabin interior noise level through a variety of mechanisms. These mechanisms include vibrations caused by aerodynamic excitations and re-radiation from the glass panels, exterior noise transmitted and leaked through door seals including gaps and glass edge, and transmission of airborne noise generated by the interaction of flow with body panels. It is of vital importance to predict both the flow fields and the acoustic sources around the vehicle to accurately assess the impact of wind induced noise inside the cabin. In the present study, an unstructured segregated finite volume model was used to calculate the flow fields in which a hexahedron grid is used to simplify the vehicle geometry. A large eddy simulation coupled with a wall function model was applied to predict the exterior transient flow fields. The mean flow quantities were thus calculated along the symmetry plane and the vehicle’s side windows. A coupled FEM/BEM method was used to compute the vehicle’s interior noise level. The total contribution of the interior noise level due to the body panels of the vehicle was subsequently analyzed.