Reduction of automobile wind-noise
Wind noise becomes dominant as automobiles driving at cruise speed (80-90 kph). A quiet driver environment is a contributing sales motivation in the sense of comfort, safety and quality. Wind noise is almost always undesired, in contrast to engine noise which in some cases provide useful feedback to the driver. Over time the engine noise has been reduced, and the relative wind noise contribution has increased. Wind noise will become even more pronounced in the future in regard of hybrid or full electric propulsion. In product development, a predictive numerical method for wind noise is needed. For engine noise there are well established tools and methods available. However, when it comes to wind noise, many areas of CAA (Computational Aero-Acoustics) are still active research areas, meaning that methods and tools are not so established and mature as those for aerodynamics. This project aims to establish a fundamental understanding about how noise sources are created by external turbulence around automobile bodies and how the noise sources depend on geometrical complexity and flow speeds. With a fundamental understanding of noise source generation, it will be possible to develop a set of design guidelines and virtual methods that can be used to evaluate, predict and optimize the behavior of typical exterior shapes used on automobiles. The techniques will be beneficial in the product development process, to predict problems already before a product has been built and reduce physical testing. The goal is to develop a fast and robust approach for predicting the dominant noise sources in the exterior flow field.