The Vehicle Noise Control Engineering Academy covers a variety of vehicle noise control engineering principles and practices. There are two concurrent, specialty tracks (with some common sessions): Vehicle Interior Noise and Powertrain Noise. Participants should choose and register for the appropriate track they wish to attend. The Vehicle Interior Noise track focuses on understanding the characteristics of noise produced by different propulsion systems, including internal combustion, hybrid and electric powered vehicles and how these noises affect the sound quality of a vehicle’s interior.
The Vehicle Noise Control Engineering Academy covers a variety of vehicle noise control engineering principles and practices. There are two concurrent, specialty tracks (with some common sessions): Powertrain Noise and Vehicle Interior Noise. Participants should choose and register for the appropriate Academy they wish to attend. The Powertrain Noise track focuses on noise and vibration control issues associated with internal combustion, hybrid and electric powered vehicles. The vehicle in this case includes passenger cars, SUVs, light trucks, off-highway vehicles, and heavy trucks.
Due to their remarkable efficiency and efficacy, chevrons have emerged as a prominent subject of investigation within the Aviation Industry, primarily aimed at mitigating aircraft noise levels and achieving a quieter airborne experience. Extensive research has identified the engine as the primary source of noise in aircraft, prompting the implementation of chevrons within the engine nozzle. These chevrons function by inducing streamwise vortices into the shear layer, thereby augmenting the mixing process and resulting in a noteworthy reduction of low-frequency noise emissions. Our paper aims to conduct a comparative computational analysis encompassing seven distinct chevron designs and a design without chevrons. The size and configuration of the chevrons with the jet engine nacelle were designed to match the nozzle diameter of 100.48mm and 56.76mm, utilizing the advanced SolidWorks CAD modeling software.
In this paper, we propose a novel Split Ring Resonator (SRR) metamaterial capable of achieving a total bandgap in the material’s band structure, thereby reflecting air-borne and structure-borne noise in a targeted frequency range. Electric Vehicles (EVs) experience tonal excitation arising from the switching frequencies associated with motors and inverters, which affects occupant perception of vehicle quality. Recently proposed metamaterial designs isolate either air-borne noise or structure-borne noise, but not both. To achieve isolation of both air-borne and structure-borne acoustic energy associated with these tonal frequencies, we propose a metamaterial supercell with transverse and longitudinal resonant frequencies falling in the desired bandwidth of the total bandgap. We calculate the resonant frequencies and corresponding mode shapes using Finite Element (FE) modal analysis.
Polyurethane foams (PUF) are a class of cellular polymers with a large range of applications. It is possible to control some properties of PUF by adjusting some chemicals, aiming to reach the best performance with lower cost, weight and process easiest. On the same way, graphene and its derivatives may be used for the modification of PUF, aiming to improve many properties. Depending on the dispersion technique, increases in mechanical, dynamical mechanical, thermal and acoustical properties may be reached, even when a low content of the nanomaterial is employed. This brief review presents some techniques used for the dispersion and incorporation of graphene and its derivatives into PUF, focusing on the enhancement of acoustical applications. Some techniques such as mechanical stirring, sonication and layer-by-layer are presented. It was observed that depending on the techniques, a real and significant difference was observed in some properties, mainly in acoustical
The China Automotive Technology and Research Center (CATARC) has completed two new wind tunnels at its test center in Tianjin, China: an aerodynamic/aeroacoustic wind tunnel (AAWT), and a climatic wind tunnel (CWT). The AAWT incorporates design features to provide both a very low fan power requirement, 3.1 MW at 250 km/hr with a 28 m2 test section, and a very low background noise, 58.2 dB(A) at 150 km/h, putting it amongst the quietest in the automotive world. These features are also combined with high flow quality, a full boundary layer control system and 5-belt rolling road (producing a 5 mm block height boundary layer profile), an automated traversing system, and a complete acoustic measurement system including a 3-sided microphone array. The CWT, located in the same building as the AAWT, has a flexible nozzle to deliver 250 km/h with an 8.25 m2 nozzle, and 130 km/h with a 13.2 m2 nozzle.
In this study, a novel selective matching logic for wheel/tire was proposed to reduce vehicle driving vibration caused by wheel/tire non-uniformity. Furthermore, validation of the new logic was performed via the matching simulation/in-line matching evaluation. The RFV theoretical model was established by considering the theoretical model of the existing references and the wheel/tire assembly mechanism, and the model was validated using ZF's HSU equipment used as standard equipment in the tire industry. The validity of the new matching logic was verified through matching simulation and mass production in-line evaluation. In conclusion, the novel logic presented in this paper has been effectively proven to reduce the RFV caused by wheel/tire, and it is being applied to mass production.