Learn about 4 acoustic engineering challenges when enhancing Electric Vehicles' acoustic performance

Electric vehicles inherently have quieter powertrains compared to traditional internal combustion engines. While this provides a more serene cabin environment, it also amplifies other sources of noise that were previously masked. Let's delve into the toughest challenges faced in this pursuit:

1. Electric vehicles often rely heavily on electrically driven heating, ventilation, and air conditioning (HVAC) systems. These systems can generate noise due to fans, compressors, and airflows. It is crucial to design and optimize HVAC components and their integration within the vehicle to minimize noise while maintaining efficient thermal management.
2. Although electric powertrains are generally quieter, they are not entirely silent. High-frequency electric motor whines, gear noises, and power electronics can contribute to interior noise. Balancing the reduction of these noise sources with other performance requirements is a constant challenge for EV makers.
3. With reduced powertrain noise, road and tire noise become more noticeable to vehicle occupants. To reduce the noise emissions generated by the interaction between tires and the road surface, EV makers and tire suppliers must collaborate more closely in optimizing tire designs and materials.
4. The challenges in sound package design for electric vehicles is all about achieving optimal noise insulation and cabin comfort without compromising the vehicle's weight and energy efficiency. Engineers must find innovative solutions to effectively reduce external noise sources, such as road and wind noise, while considering the unique acoustic characteristics of electric powertrains.
5. Auralization in electric vehicles (EVs) presents another toughest engineering challenge for is creating realistic, immersive sounds while ensuring pedestrian safety and regulatory compliance. This involves accurately reproducing unique electric powertrain sounds and designing effective alert systems without imitating combustion engine noises, all while meeting stringent regulations and providing an enjoyable journey.
6. The absence of the internal combustion engine and associated ancillary equipment makes wind noise a major source of interior noise in Electric Vehicles. Engineers must be able to predict aeroacoustics noise (AVA) accurately and early to minimize turbulent airflow interactions while maintaining aerodynamic performance.

Stringent noise regulations, particularly in urban areas, demand EVs to comply with specific noise level thresholds to ensure pedestrian safety. Delivering right the first time upon the growing standards for exterior noise compliance poses a significant challenge for vehicle engineers.

1. To address the concern of silent EVs posing a potential hazard to pedestrians, regulations mandate the use of Acoustic Vehicle Alerting Systems (AVAS) to generate artificial sounds. The challenge lies in creating sounds that are recognizable, harmonious, and provide adequate warning without being intrusive or disturbing to the surrounding environment.
2. Meeting the prescribed noise level thresholds and certification requirements for pass-by-noise is an ongoing challenge. EV makers need to develop comprehensive testing methodologies and ensure that their vehicles consistently comply with regulations across different operating conditions and driving scenarios.

To overcome the above challenges effectively, acoustic engineers have been relying on advanced simulation tools. However, integrating and optimizing these tools within existing development processes can pose challenges related to data accuracy, model complexity, and simulation fidelity. Ensuring seamless integration and efficient utilization of simulation tools is crucial for achieving optimal acoustic performance in EVs.

Solving each one of these challenges itself is a complex task due to the interoperability and interconnection of the required engineering disciplines – a seemingly insignificant design change in one area could impact all other areas of the vehicle’s acoustic performance. OEMs must figure out the solutions to all these tasks equally at the same time and commit to the optimal design early with confidence. This adds complexity on top of complexity and represents overall the most difficult challenge for automakers.

Conclusion | Imagine the power of your very own digital test facility

Now, imagine the power that automakers could harness from having their own digital test facility: It is immense! By leveraging advanced simulation within a virtual prototyping approach, automakers can significantly reduce costs and time associated with hardware testing, allowing for faster and more efficient development cycles. This digital approach empowers engineers to efficiently explore a wider range of design iterations, holistically optimize acoustic performance, and ensure first-time-right compliance with regulations, ultimately accelerating innovation and improving the overall quality of their vehicles.