Test The Limits

Accelerating Race Car Design Through CFD Simulations

By Exa

June 03 2015

Race car drivers feel the need for speed. Whether they’re hugging the curves at Circuit de la Sarthe or accelerating down the final stretch at Indianapolis Motor Speedway, race car drivers want to go fast, regardless of aerodynamics. Fortunately for them, engineers can optimize a race car’s aerodynamic efficiency. The biggest challenge for these engineers, however, is determining the best ways to modify or improve vehicle components to design high-performance race cars that outperform the competition.

Vehicle aerodynamic effects usually become noticeable around 50 mph, according to Hot Rod Magazine. Engineers are responsible for optimizing a race car’s shape and proportions to reduce aerodynamic effects, including wind resistance and the losses typically associated with the requirements for cooling flow through the engine compartment. Motorsports engineers are always seeking ways to bolster a vehicle’s aerodynamic efficiency rather than the alternative – modifying the engine to get more horsepower to overcome aerodynamic effects.

To achieve their race car design objectives, engineers frequently use on-road and wind tunnel tests to assess vehicles in controlled environments. However, physical tests have limitations and require costly, time-intensive prototypes. If design issues are only identified after a physical prototype is made, they could be forced to make late-stage design change modifications – an expense no motorsports team wants.

A race car’s aerodynamic efficiency is driven by shape parameters such as angles, radii and dimensions. Engineers need to be able to refine the vehicle’s shapes throughout the design process, and Computational Fluid Dynamics (CFD) simulations allow them to do just that. As the race car design progresses, engineers can conduct CFD simulations to collect fluid flow measurements and study the impact of aerodynamic panels and devices such as spoilers, wheel deflectors and underbody covers. Engineers also can leverage CFD simulations to evaluate the trade-offs between these components and other vehicle constraints and optimize the size and positioning of all race car parts.

An efficient race car is a proven winner – in fact, an Asian automaker used CFD simulations to design its electric race car for the 2014 Pikes Peak International Hill Climb in Colorado, USA. The manufacturer used CFD simulations to examine the race car’s aerodynamic capabilities and reduce downforce. Ultimately, the new race car won its premiere motorsports event.

Exa® Corporation’s simulation software helps engineers produce better vehicles and equipment, and we are proud to provide simulation-driven design capabilities for two of the biggest names in auto racing. Exa has partnered with former 24 Hours of Le Mans winner of the LMP2 class, OAK Racing, and world-renowned automaker Onroak Automotive to produce new, more advanced vehicles.