Eventos Anais de eventos
ENCIT 2016
16th Brazilian Congress of Thermal Sciences and Engineering
COMPARISON OF EXPERIMENTAL METHODS TO MEASURE THE AEROACOUSTIC NOISE OF AUTOMOTIVE ROOF CROSSBARS
Submission Author:
Mauricio Ramacciato Massarotti , SP
Co-Authors:
William Wolf
Presenter: Mauricio Ramacciato Massarotti
doi://10.26678/ABCM.ENCIT2016.CIT2016-0071
Abstract
Aeroacoustic noise reduction is one of the growing concerns in the automotive industry. With the advances in the suppression of powertrain and tire airborne noise, wind noise has become the dominant noise source propagating to the passenger cabin in cruising speeds. Automakers have invested a reasonable amount of resources to investigate noise mechanisms and mitigate them, in order to meet aggressive comfort requirements. The most severe aeroacoustic noise phenomena in ground vehicles are the ones with a tonal nature. The presence of discrete tones during vehicle operation is unacceptable, and one of the most critical components in terms of noise performance are the roof-mounted luggage carriers, which typically have a leading crossbar with direct exposure to the airflow. The tonal noise from roof bars, when not addressed, can be very annoying to the customer. Nowadays, most of the applied solutions to this aeolian tone are empirical, sustained by the fact that commercial crossbar profiles are not as blunt as a cylinder, neither as thin as a wing section. The objective of this project is to investigate the noise mechanisms involved in typical crossbar shapes experimentally. The first part of the study was made by correlating measurements made on-track at the General Motors Brazil Proving Ground and in the Aeroacoustic wind tunnel of General Motors North America. Interior and exterior sound pressure level measurements taken on-track and at the wind tunnel were compared. The results show that exterior microphones used on-track are capable to properly capture both tonal and broadband noise contribution of the crossbars despite of the background noise, thus being the method adopted to continue this project.
Keywords
Aeroacoustics, automotive, experimental development, wind noise, Aeroacoustics, automotive, Blunt body, wind noise, wind noise, Blunt body, Aeroacoustics, Aeroacoustics, automotive, experimental development, wind noise, Blunt body, Aeroacoustics, automotive, experimental development, wind noise, Blunt body
