A Karman vortex street is a repeating pattern of swirling vortices that occurs whenblunt bodies cause a fluid to separate. The phemenon occurs in water bodies and clouds, as seen in the picture below. I modeled the vortex in Grasshopper by creating a set of vector forces, merging them, and visualizing them through lines. I then played with the Grasshopper parameters, changing the length of location and strength of the vector forces, as well as the length of the vector lines. 



A Karman vortext street off the Chilean coast (wikipedia)      


The Grasshopper script used.