Virtual Automotive Wind-tunnel Testing

Virtual twin emissions testing is already on the rise due to new European regulations that apply to all cars sold in Europe, regardless of where they were manufactured. The standard, known as the Worldwide Harmonized Light Vehicles Test Procedure (WLTP), gives consumers and regulators consistent information on fuel efficiency and carbon dioxide emissions of traditional, hybrid and fully electric cars worldwide.

Unlike previous fuel efficiency standards, however, WLTP requires each configuration of a vehicle to have its own vehicle specific emission value. The more versions and options a manufacturer offers for a vehicle, the more tests are required to evaluate those variants.

Simulation for virtual wind-tunnerl testing. (Image © Dassault Systèmes)

To physically test all variants of every vehicle in a wind tunnel would require more time than the world’s available facilities can support, and building new wind tunnels to meet cyclical regulatory requirements is inefficient. So, too, is manufacturing all prototypes of all the vehicle variants for testing, transporting them to the wind tunnels, and operating them for the tests.

In a pure application of virtual twins, however, vehicle manufacturers have lobbied regulators for permission to test virtual variants of their automobiles in virtual wind tunnels. This reduces the need for physical wind tunnels, physical cars, and physical tests that release CO2; it also enables manufacturers to test their vehicles before production builds are available, and to make design changes if the results fail to meet targets.

Any delay in receiving certification could cost an automaker billions of dollars. Therefore, a number of automakers teamed with Dassault Systèmes to develop virtual testing protocols using SIMULIA CFD/fluid solutions. The virtual tests have been proven to provide results that are virtually identical to physical tests. 

In addition to accuracy, the virtual twin process certifies an entire vehicle family in days, not the weeks required for physical testing. Simultaneously, manufacturers can test for ways to reduce vehicle weight; increase powertrain efficiency; refine the engineering of electric drivetrains; improve tire engineering; and simulate the vehicle’s performance in adverse conditions, including rain, snow and high wind.