Abstract
Keywords:
Microphone, Surface Pressure, Aero-acoustic Noise
Abstract
For aero-acoustic noise evaluation, it is desired to measure surface sound pressures in the vicinity of sound sources in order to identify and qualify each source. Conventional methods require microphones to be flush-mounted on the measurement surface making it difficult to apply to the actual vehicle. Recently, introduction of the 2.5 mm thick “Surface Microphone” has made it possible to measure surface sound pressures more easily. In this report, the validation test is done by comparing the new surface microphones method and the conventional method. The new surface microphone method is found to be superior to the conventional method. Moreover results of the surface microphones method, applied for verification of the flow speed effect on the roof, the small protuberance effect on the roof (e.g. antenna base), and the door mirror effect on the door and the side door window is reported. The conclusion is that the new method is useful not only for verification of already-known phenomena but also for bringing new discoveries.