The sound of silence
Magnus Moore is usually met with multiple blank faces when he explains his job; which is good, because he’d rather you didn’t detect exactly what he does for a living.
“Most people have no idea what I’m talking about when I say I’m a wind noise engineer. In itself, it’s very simple, I manage the noise created by wind as it flows around the car. For instance, if you close your car window but it still sounds slightly open, that’s a problem.”
He admits that there is no such thing as an average day. He and his colleagues are brought into the vehicle design process early and remain involved throughout. It starts with reviewing the initial design sketches and then progresses to detailed styling elements, which contribute to making a significant impact. The theory of the digital simulation is then validated by using clay models in a wind tunnel to visualise and test the smallest details of the design. This iterative process continues as the wind noise team collaborate with styling and vehicle engineering teams to further refine the design surface to achieve the optimal performance.
“We use digital simulation tools long before there is an actual vehicle to check, then we have an extensive ‘physical test’ program to validate the performance. As part of this we are constantly experimenting with new cutting-edge analysis tools which seek to improve the correlation between the digital and physical activities.”
These simulations assess many aspects of air flow, even ensuring sufficient cooling airflow through the engine bay which is important when, say, towing a heavy caravan up a steep hill. The simulations also aid understanding what the noise could be like whilst sat in various places inside the car, to ensure all the passengers will have a positive experience.
For Magnus the thrill comes from seeing vehicles on the road and knowing that he’s played a role in making that happen.
“I have that back story, which is really special. I look at other cars and I think about how their story might have evolved. To me, air flow is very visual, I can imagine the wind going over the car and can see the changes which were made to improve its aerodynamics or wind noise. With cars which I have worked on, I can look at the overall design and recall the detailed changes we made, and feel proud when I see how it has all come together.”
Those changes are significant, even if not noticeable until they’re pointed out. On today’s Nissan Qashqai there are numerous subtle touches to the design which have been made purely to improve aerodynamics and reduce wind noise. For example, the curved surfaces around the rear lamps (see above image) carefully manage airflow at the rear of the vehicle, while the spiked vortex generators (see below image) reduce drag under the engine cover.
In the quest for aerodynamic perfection, it is not just about looking ahead. One of the most aerodynamic cars was originally designed in the late 1930s in Germany. Named the “Schlörwagen”, it was an experimental vehicle design that – whilst entirely impractical for a modern car – continues to inspire engineers of today.
“A raindrop is traditionally seen as one of the most aerodynamic shapes in the world but if this design were applied the car, where would you put the wheels, the passengers or their luggage! It’s not easy, Europe is probably our most challenging market due to the variety of driving styles, road conditions and customer expectations.”
The challenge is also about meeting the demands of a high-volume manufacturing business. With thousands of cars being produced at our manufacturing plants each week, great care has to be taken to ensure the continuity and quality. Getting it wrong can cause a big impact. It’s something Magnus keeps front of mind.
“It is very different to a smaller company where you might make spur of the moment decisions and can manage any unintentional consequences. At Nissan, as a graduate I used to think ‘why is this taking so long’, but after gaining some experience and understanding of the scale of our operations, it became much easier to see the good reasons behind it.”
Evolving technologies are also impacting Magnus’ role; “Managing aeroacoustics is even more challenging on electric vehicles such as the Nissan LEAF because there is minimal engine sound to mask wind noise. Addressing that is one of the biggest challenges that we have faced in recent years.”
As we prepare for the rapid growth of electric vehicles, the sound of silence has never been so important.