This post was originally published in February 2020.
SIMULIA’s solutions take a comprehensive approach to identifying and ranking different sources of noise in order of their contribution to the sound experience of passengers, allowing engineers better control over these sources. These solutions enable study of the impact of exterior design changes as well as different sound package options to reduce the wind noise inside the cabin, allowing engineers to design vehicles that rate highly in terms of customer satisfaction.
You’ve probably been in this scenario before: it’s a beautiful day, and you’re cruising in a car with a traveling companion or your favorite playlist on the stereo as you sail down the highway. Depending on the quality of the vehicle design, this can either be an exhilarating experience or an annoyance, as conversation can become difficult due to the roaring of the wind. One solution is to raise your voice or turn up the music volume, but that eventually causes hoarseness or fatigue.
Wind noise in vehicles is a common complaint from buyers – everyone wants a quiet ride, and wind is one of the greatest contributors to noise in a vehicle. You may think that there’s not much to be done about the wind, but that’s not true – through subtle modifications of the vehicle’s shape and the placement of its external parts, such as windshield wipers, wind noise can be mediated to an extent.
Wind noise is caused by air flow moving over the exterior of the vehicle. Traditional testing methods to assess wind noise and its impact on passengers inside the vehicle have to wait until late in the vehicle’s development, after a quality prototype has been made. However, because wind noise is so dependent on the exterior shape of the vehicle, mediating it this late in the development process often means extensive and expensive redesign.
In some cases, it’s too late to make those kind of design changes, and so manufacturers must rely on other means to dampen wind noise, such as additional sound packaging or acoustic glass attenuation, adding weight and cost to the vehicle. Adding weight is an issue in itself; besides making the vehicle more expensive, additional weight can risk not meeting fuel efficiency targets.
Predicting the level of noise caused by exterior elements is not the only critical task; engineers must also be able to assess how the sound will be perceived by the passengers riding inside the vehicle. Only by predicting how the exterior elements will affect the interior passengers can engineers effectively design for a satisfactory customer experience.
Another issue is that wind tunnel wind conditions do not represent the upstream turbulence changes experienced by vehicles at on-road wind conditions. Therefore, the shapes optimized for wind tunnel wind conditions may provide sub-par wind noise performance at on-road wind conditions. Road tests are done too late in the design process to capture this issue and fix it. This leads to vehicle designs with high overall noise and high modulation of noise inside the cabin at on-road wind conditions, significantly affecting customer comfort.
Simulation used in the early stages of vehicle development can prevent these complications and roadblocks later on. SIMULIA has developed digital solutions for vehicle acoustics using its best in class solutions PowerFLOW, PowerACOUSTICS and wave6 which address these challenges and help engineers design vehicles with better wind noise performance.
The use of these digital solutions in the vehicle development process minimizes late-stage failure risks, allowing engineers to evaluate wind noise performance at various on-road conditions early in the design process, identify potential issues and fix them before the design is frozen.
Learn more about SIMULIA’s solutions, here.
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