By Daniel V. Schroeder, Physics Department, Weber State University
This is a simulation of a two-dimensional fluid. Initially the fluid is flowing from left to right, and a linear barrier (shown in black) diverts the fluid and creates vortices. The colors indicate the curl, or local rotational motion, of the fluid. Use the controls to adjust the flow speed and viscosity, draw different barriers, drag the fluid around, plot other quantities besides the curl, show the force exerted by the fluid on the barriers, and measure the fluid's density and velocity at any point.