Swirling flow in a box with piecewise constant initial data.
Edge velocities are stored in aux array (see setaux.f) with velocity specified by differencing the streamfunction psi.f The velocities are time-dependent giving reversing flow. These velocities are computed in b4step2.f.
In theory the solution should agree with the initial data at times t = 2, 4, etc., but because of the numerical diffusion this won't happen.
Download directory in compressed tar file format (Note: Please unpack the tar file in your CLAW home directory.)