This problem illustrates periodic vortex shedding for flow past a block in a narrow channel, FlowPastBlockNarrowChannel.feb.zip. Back flow and tangential flow stabilizations are used on the outlet face.
The movie displays contours of the z-component of vorticity to visualize vortex shedding. A vector plot of the nodal fluid velocity is superposed on the contour plot as well. The PostView Time settings use a fixed time step of 0.5 s to speed up the animation, though the actual analysis used 0.1 s time increments.