Noise measurements and examination of noise sources in passenger cars

Folyóirat címe
Folyóirat ISSN
Kötet címe (évfolyam száma)

This thesis aims to get and measure the noise emitted by the passenger vehicle according to ISO 5128-1980, ISO 5130:2019, and the Soundcam device. The thesis starts with the theoretical background about the sound, human hearing, and the effect of noise on human health. After that, it addresses the different sources to the overall noise of the vehicle that experienced by the occupants, such as engine noise, tire noise, intake and exhaust noise, gearbox noise, and aerodynamics noise. And finally, ISO 5128-1980, ISO 5130:2019 methods, and SVAN 971 Sound level meters and Soundcam 2.0 devices, which are used in the measurements, are explained in details. The vehicle used in this test is MK7 Golf Volkswagen. The practical part of the thesis involves the measurement results at the different microphone positions, and at each vehicle operating conditions, which are the steady speeds, the full throttle acceleration, and the stationary mode inside and outside the vehicle. Then, the L_(AF max) average values are evaluated and compared at each condition, which serves to identify the noise sources and the difference in the results. The highest average value of L_(AF max) at the steady speeds is when the speed of the vehicle reaches 120 km/h, while the lowest value at 60 km/h speed. For the full throttle acceleration condition, the noise level in the driver seat is higher than the noise in the passenger seat. The L_(AF max) average value at stationary mode outside the vehicle is higher than the noise inside, and the driver seat has the lowest value at this measurement. The last part of the results is the Souncam average results, which are high at the front side, and low at the rear of the vehicle. The reasons for the results difference are explained in details in the discussion section. Finally, some solution ways for reducing the noise of the vehicle were introduced, such as using damping materials, the engine insulation, and improve some parts of the vehicle. In summary, this thesis offers significant complexities of vehicle noise, and offering valuable perspectives and solutions to minimize the noise impact on the environment around us.

Noise measurements