Airflow simulation. The image shows the flow of air over an open-wheel race car. The streamlines are coded by velocity magnitude where blue is low and red is high. In the case of aerodynamic design of an open-wheel race car, the initial concept model would represent the wheels, body, under tray (diffuser), rear and front wings. With this simple geometry setup you can freely move or modify the airfoils and body independently to find an optimal configuration based on lift and drag values from the Computational Fluid Dynamics (CFD) simulation.
(Source: National Center for Manufacturing Sciences)