German auto parts manufacturer Mahle has created a series of low-noise fans for active cooling systems with power ranging from 300 W to 35 kW. Low noise levels of fans have become popular with the advent of electric vehicles, and the wings of owls – silent night hunters of small animals – have become a good example for borrowing this feature.
Image source: Mahle
Electric vehicle chargers and inverters are subject to increasingly extreme operating conditions. This is due to the fact that the battery charging time is reduced, which automatically increases the charging currents and, accordingly, the growing power. But even in long-charging mode, the cooling systems of an electric vehicle’s electrical system can create significant noise, which will be especially annoying on a warm summer night. It should also be expected that heavy electrical equipment – from electric trucks to special equipment – will be equipped by default with a powerful electrical subsystem and will require non-trivial solutions for heat removal.
The Mahle company, as they report, used artificial intelligence to select candidates for quiet behavior among owls, swordfish, bats and other living creatures with minimal noise levels. Ultimately, the choice fell on owls and the peculiarity of their feathers at the ends of their wings. It should be noted that this feature has been repeatedly used in fans of a wide range – from industrial to cooling systems for computers and laptops. In general, the AI will not give bad advice.
According to the developer, the use of blades with tips, like those on the wings of an owl, halved the level of noise created by the impeller – to 4 dB. “It’s like turning off one speaker on a stereo system,” the company explained.
The new blade design also provides 10% more efficient operation and is 10% lighter than a conventional fan design. This difference may not be noticeable to electric vehicle drivers, but when combined with other factors, it makes electric vehicles more comfortable to drive.