Automotive aeroacoustics: An overview

Abstract

The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. AbstractVehicle aeroacoustic performance has a strong influence on customer perception and also has importance for safety and comfort. Wind noise performance was once differentiated by the quality of sealing. Today, achieving competitive wind noise performance also depends on minimising aeroacoustic noise sources generated by the vehicle form, and on attenuation in the noise pathway from sources on the exterior to the vehicle interior. Attenuation in the noise pathway from sources on the exterior to the vehicle interior, especially through glazed surfaces, will continue to play an important role in controlling cabin noise, with a particular emphasis on achieving attenuation efficiently in terms of component mass. The human brain is not only sensitive towards the level of steady broadband noise, but distinctive features such as tonality or modulation draw the attention of the vehicle occupant and impact negatively on perception. Complex indices are often required to define good wind noise performance. This includes the consideration of multiple frequency bands and effects of the range of yaw angles experienced on-road. A key to achieving future vehicle refinement is bringing together an understanding of unsteady onset flow conditions, their impact on cabin sound pressure level and modulation and in turn the impact of noise level and modulation on psychoacoustic perception.

Reduced-order modeling of pressure excitation on automotive front side window

“…The turbulent pressure on the side window can excite the side glass to vibrate. For a plane plate, the flexural wavenumber 38 can be expressed by equation (12) where K flex is the flexural wavenumber, r 2 is the density of the plate, y is Poisson's ratio, E is Young's modulus, and h is the thickness of the plate. For the typical working conditions of an automobile, the related parameters are shown in Table 2.…”

“…The side mirror and A-pillar generate a wider range of scales of vortex structures, which make the pressure excitation on the front side window more complex. 12 There is a need of new description methods which can reflect the temporal and spatial properties of the pressure excitation on side glass in the exact pace to further understand the pressure excitation on the side window and to perform the comparative study with the vibration of the side glass.…”

Study and Design Frontal Area of a Car to Curtail Aerodynamic Noise

“…Also, in early days there was no focus on exterior body to limit the aerodynamic noise only the seals of the vehicle use to be considered to supress the noise generation of aerodynamic noise. [4] CHEN Xin (2012) et al, in this paper computational fluid dynamics simulation method is used by making a surface model of the car and providing boundary conditions to simulate the whole process and get to know in which part of the model car is the aerodynamics noise is more. By this analysis also get to know from which interior regions of car is the noise is being heard by the people sitting in the car's cabin compartment.…”

Experimental Study on a Generic Side-View Mirror with Slotted Cylindrical Foot

“…Automobile noise is composed mainly of engine noise, tire noise, and wind (aerodynamic) noise (Li et al 2011). When a car runs at high speeds, aerodynamic noise becomes the dominant noise of the vehicle (Liu et al 2018), in which the side-view mirror is one of the aerodynamic noise sources Levy and Brancher 2013;Murad et al 2013;Oettle and Sims-Williams 2017). The high-speed airflow separation from the mirror surface leads to severe pressure fluctuations on the side window (Zheng and Li 2012;He et al 2020), which plays a significant role in the vehicle interior noise (Wang et al 2010;Yang et al 2014;Yao et al 2018).…”