Abstract:
The acoustic characteristics of rubber primary bulb weather seals, used around road vehicle doors to isolate the passenger compartment from water infiltration and air leaks, were investigated experimentally. Short seal samples were mounted within the test section floor of a small, quiet, low-speed wind tunnel adjacent to a soundproof anechoic enclosure. The geometry of the fixture hosting the samples approximated that of a typical vehicle door gap. The results demonstrated the importance of small air leaks and that of the flow-induced Helmholtz resonance of the door cavity on the acoustic performance of the seal assembly. The noise reduction of perfectly sealed systems appeared to be slightly higher with a flow excitation than that measured with a random acoustic excitation using a reverberation room method. The experimental results were compared to the predictions from a two-dimensional lumped-element analytical model based on the assumption that the seal behaves like two limp membranes separated by a closed cavity. The influence of seal compression, rubber properties, and cavity geometry were investigated. [Work supported by Cooper Tire and Rubber Company.]