Wiper blades and windshield influences on wiping aerodynamic noises

摘要

Over the past years, great effort has been made to reduce the noise level of the main sources inthe passenger cell. However, previously masked noise sources have now become more annoying.Decreasing the global and modulation levels of the wiper system aerodynamic noise at speedsabove 120 kilometers per hour has become an important topic. New aeroacoustic blades havebeen designed and tested in comparison with standard ones, in real road conditions. Severalacoustic criteria for annoyance have been selected, and classification is now possible; transferpaths have also been studied, highlighting the influence of the windshield type. Acousticmeasurement tests of the same type have been performed. Various thicknesses and dampingmaterials of the windshield have been tested. The 'flat blade' design acoustic characteristics arevery satisfactory. When the flat blade and the 'acoustic PVB' damping interlayer of thewindscreen are associated, the aeroacoustic noise is nearly non perceptible. In this case, theinfluence of the side window is more apparent. The results also show that a good aeroacousticwiper noise compromise can be found between weight decrease (smaller thickness) and acousticperformance using the 'acoustic PVB'. Comparison with numerical simulation shows goodcorrelation.