DEARBORN - Ford is the first automaker in North America to use a state-of-the-art tool called an exterior microphone array system for aeroacoustic vehicle wind testing.
The tool – an apparatus equipped with a camera and dozens of highly sensitive microphones – will be used in Ford’s Wind Tunnel 8, which recently marked its 10th anniversary.
The system will enable engineers to measure exterior noise sources on a vehicle much earlier in the production process when the car or truck is still in the clay model phase. Ford engineers typically utilize Aachen Heads – mannequins with microphones in the ears that record and measure the sounds of the vehicle at various speeds – in vehicle testing but Aachen Heads cannot be put inside vehicles that are made of clay.
“Our approach before was to mock up the exterior shape of a current product to make it look like the future vehicle,” explained Bill Gulker, supervisor, Ford Interior Quietness Engineering. “But our ability to do that accurately had many limitations, and the testing process involved a lot of trial and error to isolate the sources of unwanted noise.”
Using the new system, engineers will be able to measure and actually “see” noise coming off the clay model exterior in a very precise way.
“An image that most people are familiar with is a satellite weather map. It will look just like that but instead of a map as a background you will see a computerized image of the car with red or green spots indicating noise or quiet areas,” explained Gulker. “We will be able to pinpoint exactly where the noise is coming from and resolve the problem much earlier on in the product development process.”
Gulker says the new technology will save Ford hundreds of hours of wind tunnel testing as well as thousands of dollars in testing costs each year.
“There will be no time wasted with trial and error,” he said. “The system will tell us in a very efficient way what exterior areas of the vehicle we need to work on to optimize a vehicle for wind noise.”
The detailed flow information from the system also will enable engineers to bring computer simulations online faster, which ultimately reduce reliance on costly wind tunnel testing.