Flowsquare

Due to its unique interface of generating boundary conditions using a paint software, simulations of flows around various objects are quite easily carried out with Flowsquare, and such simulations are sometimes called numerical wind tunnels. This is an example of such cases where a car is placed in a constant speed flow. Ground effect can also be taken into account in the simulation by using a moving boundary as a road surface. As clearly seen in the movie below, there is a backflow behind the car, moving up and down frequently due to the interaction between flows through the car-top and car-bottom.