BMW has opened the world's largest vertical wind tunnel (video)
The new Aeroacoustics and Electric Drive Centre (AEC) at the BMW Group's Research and Innovation Centre (FIZ) in Munich has become operational. It replaces the old aeroacoustic wind tunnel, which had been in operation for almost 40 years.
Here's What We Know
The AEC consists of two buildings that were constructed in the excavation. The first is a multi-purpose part with workshop, test and measurement equipment. The second is a unique wind tunnel just under 100 metres long, 45 metres high and 25 metres wide. BMW claims it is the world's largest vertical acoustic wind tunnel and at the same time the quietest.
Why vertical?
The wind tunnel was designed vertical to maximise the efficiency of the construction site. It was the only way to fully meet all the requirements for both buildings and realise it in the existing space.
Aeroacoustics E-Drive Centre (AEC). Photo: BMW
The entire building, from the 3m thick floor slab to the façade, is soundproofed against noise from the surrounding area. All construction work was carried out in a functioning facility.
What else is remarkable about the facility?
It has a 4.5 MW fan capable of delivering up to 100,000 m³ of air per minute at a speed of 250 kilometres per hour. The wind tunnel is designed as a semi-free-field acoustic space. This means that, with the exception of the soundproof floor, there are no sound reflections. This allows a realistic simulation of the situation on the road. The frequency range for semi-free field conditions from 30 Hz is unique to the vehicle wind tunnel and covers the entire audible spectrum.
Working with the smoke unit in the BMW Group's aeroacoustic wind tunnel. Photo: BMW
The 216 microphones allow background noise to be precisely localised with an accuracy of less than one centimetre. In addition, the wind tunnel is equipped with a laser vibrometer system for non-contact measurement of mechanical vibrations of the entire vehicle surface.
Source: BMW
