Race to the top: how advanced simulation fuelled VW's record-breaking electric ascent

A winding 1,440m ascent to the highest summit in the Southern Front Range of the Rocky Mountains – the Pikes Peak International Hill Climb, also known as the Race to the Clouds, is a unique automotive challenge.

Last June, Frenchman Romain Dumas set a new record time of 7 minutes 57 seconds in the Colorado race, the first time that an electric car held the overall record. 

After the dust settled, Volkswagen – the maker of the 680hp ID R prototype race car – praised one aspect of the project in particular. Simulation from Ansys gave the team the “competitive edge,” said VW Motorsport’s technical director François-Xavier Demaison. We caught up with the Ansys team late last year to hear how they managed it.

Multi-physics modelling

The 20km run presented several major challenges. The eminently flammable batteries were air-cooled to reduce weight, while the lower air density at high altitude meant the car would perform differently. Modifying a wind tunnel or repeatedly testing the batteries under strain, risking fires, would be unsafe, “expensive and time consuming,” said Ansys engineer Akeel Auckloo.

Instead of physical testing, Ansys used its multi-physics modelling software to assess the impact of the climb on a CAD model of the car, simultaneously testing aspects including aerodynamics and thermodynamics. The software simulated the lower air density, showing how the car would perform – and the results were backed up by the record-breaking run. 

Simultaneously running hundreds of simulations allowed engineers to make extensive alterations to the ID R, either by updating the car’s design after modifying the CAD model within the software or by tweaking the battery’s chemical make-up. The process “achieved the perfect combination of energy management, electric propulsion and aerodynamics,” said Ansys vice-president Shane Emswiler. 

When asked about simulation’s most significant contribution, however, engineer Auckloo named “time to market”. The efficient process cut the time needed for such advanced and successful prototyping and it also required fewer people, helping cut costs – all of which could aid the development of new mass-market electric cars.  

When it comes to testing, said engineer Mike Hutt, “if you can do that faster, cheaper, with real accuracy and trust and confidence in the digital realm, then you’re on to a winner. When you do get to a physical prototype, you can be more confident in your expenditure, get to market quicker, and be more innovative.”