Acoustical Performance of Baffle Design Options for Water Management 2011-01-1622

Expandable cavity sealers have become a critical component of the overall acoustic package that contributes to the documented noise reduction in passenger car applications over the course of the last twenty years. They encompass a variety of technologies, some of which are delivered into the supply chain as bulk materials and others which are highly engineered parts and assemblies. As the market for smaller and more fuel efficient vehicles continues to expand, design architectures of the base vehicle platforms are evolving to include body designs with smaller spaces between adjacent layers of sheet metal. As this space, or cavity, between the adjacent layers of sheet metal is shrinking, the complexity of components that must be integrated into the space between these layers of steel is increasing. Complex arrays of airbags, corresponding wire harnesses, and water management tools are now standard requirements in the design process. To manage the complexity of these lightweight and fuel efficient vehicle architectures, new engineering design solutions are required to meet stringent acoustic requirements. The supply base of acoustic products to the automotive OEMs has also matured over this time period, creating a very competitive environment, both regionally and globally. Design solutions that go beyond the basic functionality of a cavity filler are becoming more common. This paper will evaluate a recent design challenge presented by an OEM to improve visibility for the driver. Here, the hardware to direct water drainage is moved from outside the windshield pillar cavity body metal to inside the cavity metal. A new cavity filler solution is conceptualized to manage this unique packaging and acoustic performance need. Although it's in its infancy, the solution, along with other means of water management, are measured for Insertion Loss and compared. This initial study supports the promise for acoustic performance of a solution that does not exist in the market today.