Search Results

A time cost effective methodology has been developed for the prediction of the A-pillar vortex formation and the side and the rear window flow separation for the purpose of wind noise assessment. This methodology combines a simplified Computational Fluid Dynamics (CFD) model and wind tunnel test data by CFD post-processing tools. The solution of the simplified CFD model provides background data for the whole flow field, but it lacks detail features such as mirror, sealing groove and glass in-set, which are locally important but difficult to mesh and require a very fine mesh resolution. The wind tunnel test data was taken in the specific areas of interest at the A-pillar, side window, rear window area, and roof from a real automotive. Then the wind tunnel test data was superposed upon the simplified CFD model to correct the numerical error due to geometry simplification and insufficient mesh resolution.

Wind noise reaches the interior of a vehicle through a variety of mechanisms including: aerodynamic excitation of vibration and reradiation from the greenhouse surfaces; acoustic transmission through door seals including gaps and glass edge leaks, and due to airborne transmission of noise generated by wind interaction with body panels. This paper presents experimental results that quantify contributions to interior noise from individual greenhouse surfaces and from airborne sources on the underbody. The measurements were carried out on a production vehicle in a wind tunnel. Greenhouse surfaces, in addition to the driver window are important contributors to interior noise along with airborne transmission of noise generated due to the flow over and through the vehicle underbody.