Acoustical Materials: Solving the Challenge of Vehicle Noise

2021 ◽  
Author(s):  
Pranab Saha

For a limited time only, SAE is offering a 20% discount off the list price of $70. Purchase today for $56. What is acoustics? What is noise? How is sound measured? How can the vehicle noise be reduced using sound package treatments? Pranab Saha answers these and more in Acoustical Materials. Acoustics is the science of sound, including its generation, propagation, and effect. Although the propulsion sources of internal combustion engine (ICE) vehicles and electric motor-powered vehicles (EV) are different and therefore their propulsion noises are different, both types of vehicles have shared noise concerns: Tire and road noise Wind noise Vehicle noise and vibration issues have been there almost from the inception of vehicle manufacturing. The noise problem in a vehicle is very severe and is difficult to solve only by modifying the sources of noise and vibration. Sound package treatments address the noise and vibration issues along the path to reduce in-cabin noise. In Acoustical Materials, readers will grasp the science of reducing sound and vibration using sound absorbers, sound barriers, and vibration dampers. Sound provides information on the proper operation of the vehicle, but if unchecked, can detract from the consumer experience within the vehicle and create noise pollution outside the vehicle. Acoustical Materials provides essential information on the basics of sound, vehicle noise source, how these are measured, how vehicle owners perceive sound, and ultimately, how to solve noise problems in vehicles using sound package materials.

2021 ◽  
Vol 263 (4) ◽  
pp. 1954-1962
Author(s):  
Eiji Yoshioka ◽  
Shin Itou ◽  
Junji Yoshida

In recent years, electric vehicles are becoming more popular. This transition makes interior noise and vibration smaller according to the engine rest and makes interior more comfortable. On the other hand, this reduction has a possibility to decrease important information for drivers. In this study, we focused on the steering vibration as the vehicle speed information and investigated the influence on the comfortableness in cabin for the compatibility through subjective evaluation test using a simple driving simulator. In the test, vehicle speed controlling task was given to the participants without speed meter at acceleration conditions. In addition, subjective evaluation about the comfortability to the presented sound and vibration was conducted after the speed recognition test. As the presented steering vibration, the following four patterns were prepared. 1: internal combustion engine noise and vibration with road and wind noise (background noise), 2: electric-powered vehicle noise without vibration (background noise without vibration), 3: tire vibration with background noise, 4: motor vibration with background noise. As the result, the steering vibration of internal combustion engine or motor was found to be suitable stimuli for compatibility between the speed recognition performance and the comfortability in cabin.


2021 ◽  
Vol 104 (1) ◽  
pp. 003685042110052
Author(s):  
Xia Hua ◽  
Alan Thomas ◽  
Kurt Shultis

As battery electric vehicle (BEV) market share grows so must our understanding of the noise, vibration, and harshness (NVH) phenomenon found inside the BEVs which makes this technological revolution possible. Similar to the conventional vehicle having encountered numerous NVH issues until today, BEV has to face many new and tough NVH issues. For example, conventional vehicles are powered by the internal combustion engine (ICE) which is the dominant noise source. The noises from other sources were generally masked by the combustion engine, thus the research focus was on the reduction of combustion engine while less attention was paid to noises from other sources. A BEV does not have ICE, automatic transmission, transfer case, fuel tank, air intake, or exhaust systems. In their place, there is more than enough space to accommodate the electric drive unit and battery pack. BEV is quieter without a combustion engine, however, the research on vehicle NVH is even more significant since the elimination of the combustion engine would expose many noise behaviors of BEV that were previously ignored but would now seem clearly audible and annoying. Researches have recently been conducted on the NVH of BEV mainly emphasis on the reduction of noise induced by powertrain, tire, wind and ancillary system and the improvement of sound quality. This review paper will focus on recent progress in BEV NVH research to advance the BEV systems in the future. It is a review for theoretical, computational, and experimental work conducted by both academia and industry in the past few years.


2021 ◽  
Vol 263 (2) ◽  
pp. 4189-4198
Author(s):  
Katsuya Yamauchi ◽  
Minori Dan ◽  
Federico Cioffi ◽  
Luigi Maffei ◽  
Massimiliano Masullo

The heating, ventilation and air-conditioning (HVAC) system is one of the most critical sources in in-vehicle noise environment, especially when cars are moving at low speed or at lower engine rotation. With the transition to electric vehicles (EV) from internal combustion engine vehicles (ICEV), the contribution of powertrain becomes lower on the background noise inside car cabins. The authors have been conducting a collaborative research on HVAC sound quality inside car cabins. In this paper the results of a subjective evaluation of HVAC sound quality were presented, that attempted to compare the perceptual differences among the two groups, i.e. EVs and ICEVs. The result revealed the difference in the noise perception among the two types of vehicles especially softer air flow rate conditions.


2017 ◽  
Vol 5 (1) ◽  
pp. 71-86
Author(s):  
Muna S. Kassim ◽  
Ammar Fadhil Hussein Al-Maliki

Internal combustion engine is a major source of noise pollution. These engines are used for various purposes such as, in power plants, automobiles, locomotives, and in various manufacturing machineries. The noise is caused by two reasons; the first reason is the pulses which created when the burst of high pressure gas suddenly enters the exhaust system, while the second reason is the friction of various parts of the engine where the exhaust noise is the most dominant. The limitation of the noise caused by the exhaust system is accomplished by the use of silencers and mufflers. The aim of this study is the reduction of the noise by changing its inlet and outlet pipe length and shape. Also the losses in noise for different length and shapes have been investigated experimentally. The results show that the corrugated pipe is preferable for noise reduction.


2017 ◽  
Author(s):  
Dirk von Werne ◽  
Stefano Orlando ◽  
Anneleen Van Gils ◽  
Thierry Olbrechts ◽  
Ivan Bosmans

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