This is a plot of the L2 norm of the control (the body force) vs. time. We see that the control is initially large (when the flow is not close to the target flow) but that at later times less control is needed to keep the flow close to the target flow. Note the slight increase in the size of the control near the final time at which control is applied (t= 1.)
The initial target and initial optimal velocity fields
The target and optimal velocity fields at t = 0.1
The target and optimal velocity fields at t = 0.3
The target and optimal velocity fields at t = 0.4
The target and optimal velocity fields at t = 0.5
The norm of the difference between the target and optimal velocities vs. time