Aerodynamics are a key part of the performance of a vehicle, and given the cost of building and testing a whole vehicle or component, simulations are a commonly adopted approach to help model their behaviour. By simulating a vehicle using computational methods such as Computational Fluid Dynamics (CFD), engineers can mimic the physical domain and run virtual wind tunnel experiments for a fraction of the price. This can allow the engineers to understand the performance of designs in advance, thus narrowing down the right design choices for the prototype stage.
Unfortunately, simulations can take several hours to run, and must be run for multiple designs for hundreds of different conditions. Furthermore, their accuracy is not perfect. For example, tyre and rim aerodynamics are notoriously difficult to model accurately, so when a prototype is created and tested on the road, the results can often drastically differ from the simulation results.