Test The Limits

Formula E Aerodynamics: Designing Electric Race Cars

By Exa

November 01 2016

Emissions-free vehicle racing is an exciting— and newly possible— concept. The FIA Formula E Series, whose inaugural season was in 2014, has now become a popular international racing series, drawing fans who want to see the latest technology at work.

 

After more than a decade away from race circuits, Jaguar Racing is a now key player in the Formula E series. Jaguar Racing’s new electric car, the ‘I-Type’ (‘E-Type’ was sadly already taken), can reach 0-60 mph in an impressive 2.9 seconds. It features a 200kw (270bhp) motor which delivers instant torque, and is also used to regenerate energy while braking, returning it to the battery and acting as a range extender. Surprisingly, while this new powertrain wastes much less energy than an F1 vehicle, it still requires lots of airflow to keep the batteries and electronics cool.

 

With industry and spectator attention naturally focused on the new electric powertrain and its unique challenges, comparatively little has been said about aerodynamic optimization in Formula E. Just like F1 vehicles, the aerodynamic optimization balances drag, cooling airflow, and downforce. Since these vehicles are heavier and less powerful than an F1 vehicle, aerodynamic drag is very important.  

 

The bodywork and wings for all cars in the series are produced by French racing tech company, SPARK, who was established especially for Formula E. Built to withstand the sharp twists and turns of the series’ street tracks, the body shapes of these cars are designed to meet the specific aerodynamic challenges of racing in close quarters and on unpredictable surfaces.

 

Key Design Elements of Aerodynamic Formula E Race Cars  

 

To produce enough downforce for the required grip to maneuver with agility, the cars have three key aerodynamic elements to consider: the front wing, the rear wing, and the shaped underbody.

 

Although the sharp pods positioned on either side of the front wing look as though they’ve been designed for extra aero-slipperiness, they are in fact a necessity to prevent wheel contact if other cars get too close. In between these pods, however, sits the clever front wing, which can be adjusted by technicians in the pit to varying levels of downforce. At the rear of the car, the deep wing also dictates levels of downforce and ensures the car’s traction and stability when cornering.

 

The underbody is quite different to its counterpart in Formula One, with large tunnels that create abundant additional downforce without causing unwanted aerodynamic drag or disruption to trailing airflow. All of these measures are perfect for enhancing traction and encouraging intensive, closely bunched racing battles.

 

Achieving Aerodynamic Electric Race Car Design Through Simulation

 

When designing electric race cars, manufacturers need access to information that will help them improve design at each stage— namely, aerodynamic data. However, this can be costly and difficult to obtain, since it traditionally involves building physical prototype and testing in a wind tunnel. Usually this can’t be done until the later stages of vehicle design, meaning that any changes needed will be expensive and likely delay the manufacturing greatly.

 

Simulation offers an answer to these challenges. Aerodynamic simulation software can accurately predict real-world transient conditions on electric race car designs, providing a visual representation of the airflow around the vehicle and through the engine bay and underbody.  Simulation can also show the effects of wheel rotation for on-road configurations, cooling fans for cooling flow conditions, and heat exchangers for resistance to the flow and flow losses affecting aerodynamic efficiency. 

 

By analyzing simulations, electric race car designers can fully grasp the aerodynamic drag acting on each part of their vehicles. They can then make alterations earlier in the design process, reducing budget needs and getting the vehicle to market faster.

 

Final Thoughts

 

Formula E is a step in the right direction for the wider auto industry, for a number of reasons. We’re seeing the exciting possibilities of a powertrain that will likely come to dominate our experience of driving over the next 50 years, and we’re also seeing how the very best in the world adapt to its associated challenges – notably regenerative braking, specialized underbodies and challenging inner-city circuits. 

 

Learn more about designing aerodynamic race cars with simulation technology.