When most people think of wind tunnels, they associate it with aerodynamic testing and drag reduction. But there is another use: controlled acoustic measurement. Normally wind and road noise testing is done on an open road, but this leaves a lot of uncontrollable variables. To overcome this, Ford developed a mobile aeroacoustic wind tunnel for this purpose specifically. The tunnel can produce wind speeds of up to 80 miles per hour- well beyond normal operating speeds. The tunnel can be broken down into its components and reassembled in a matter of hours at any Ford plant in North America.
The tunnel is constructed from two 53-foot shipping containers in parallel and one 40 foot container as a control area, with aeroacoustic vanes and internal ducting to replicate 80 mile per hour wind speed. Both of the 16-bladed fans use a 250 horsepower motor to spin them up. The other benefit of having a portable wind tunnel is it reduces time spent on the road, and in turn reduces test cycle times from weeks to just a matter of hours. This allows engineers to have a better work-life balance, and employee happiness is the key to productivity.
The cost of a full sized aerodynamic wind tunnel is roughly 50 million USD, once all the measuring and analysis equipment cost is factored in. Testing time is constantly fought for as these facilities are in very high demand by various departments and teams. But for the purposes of aeroacoustics alone, much of the equipment can be done without- and standalone sensors in the cabin are enough for testing purposes. The portable wind tunnel also allows Ford to test vehicles from off the line without delay to ensure that the seals and other components are intact. This saves time as it reduces the number of cars that slip through quality control.