All work and no play makes Jack a dull boy.
On a wing suddenly brought in motion separation develops gradually. The colours visualise the vorticity distribution.
When modeling a flow past a moving car it is important to include the effect of the ground. Observe how it is done in Flow Illustrator.
Karman vortex street developing in the flow past a circular cylinder suddenly brought to motion. The Reynolds number based on the diameter is equal to 125. Flow Illustrator shows Re based on the image height.
Flow past a circular cylinder at the Reynolds number based on the diameter equal to 25. The flow is separated but it becomes steady after the initial transient.
Flow past a circular cylinder at the Reynolds number based on the diameter equal to 2. The flow is attached and quickly becomes steady after the initial transient. As it is characteristic of two-dimensional flows at small Re, the effect of the body on the velocity distribution is felt at distances large as compared to the body size. In this case the effect spreads to the upper and lower boundaries of the computational domain, creating spurious non-physical features near these boundaries.